# 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicians greatly appreciated.



## SpeedRacer20 (Jan 7, 2004)

*The updates to this thread are going to be dated and upkept on this first posted
*This post is long winded, so here's a quick reference of things tried and parts cleaned/replaced.
*Note* that not all parts were replaced because of this problem.
Also, underneath this list I will put updates to things I've tried and or cleaned recently so it's easy to find, plus the date I did it.
VAG Pulled Code:
"16486 P0102 035
Mass or Volume Air Flow Circ.
Low Input
Sporadic DTC"
Car is a 1996 OBDII Jetta GL with 115k miles
Mobil 1 full synthetic 5w 30 (have tried different weights/oils)
Chevron with Techron Premium octane (have tried different brands)
I feel an important part of solving this problem is acknowledging the fact that the car *sometimes* runs very strong, makes *no* tinking noise inside the engine and *does not* smell like sulphur out of the exhaust. *Nor* does it always buck and hesitate on acceleration or maintaining constant speeds.
*These problems are intermittent, and sometimes seemingly completely vanish.*
*Replaced:*
All belts, including timing
Catylytic converter (tt highflow)
Exhaust manifold (had large crack)
Mass air flow sensor (bought a slightly used from 1800vw)
Coolant temperature sensor
Radiator
Transmission
Clutch
AC condenser
Bosch OEM spark plugs (old ones were dark yellow/black on tip)
Spark plug wires (Blue ignitors from tt. My original wires were Bosch OEM, and this problem has persisted through the wire changes. I don't believe my aftermarket German Blue Ignitor wires have anything to do with this problem. They have been checked thoroughly for malfunction, and I can't find a problem with them.)
Bosch distributor cap (old one had alot of corrosion on points)
Bosch rotor (old one was corroded on point)
Throttle body (got rid of CEL when installed)
Coolant change
Fuel filter
Air filter
Oil filter (of course)
O2 sensor
Manual adjust clutch cable
ECM Power relay #109 (there never was one in there to start, apparently only for OBDI cars..)
TT ECU Chip (problem existed before I ever changed out the OEM chip)
PCV hose / elbow
*Things I've cleaned, checked for snugness, checked for wear/cracks and leaks:*
Timing has been done
PCV reservoir
Air intake boot
Intake box
All ground connections that I could find in engine bay were cleaned and reseated.
ECM harness connector
All electrical point connectors were cleaned with electrical point cleaner (including MAF connector and O2 sensor connector)
Checked intake manifold for dirt/oil (where the throttle body connects) and was completely clean.
Intake boot connection to MAF, and to the throttle body.
EGR hose looks seated properly on both ends.
Checked all hoses going anywhere for freys/breaks and couldn't find a thing.
Unwrapped all wires that were wrapped in tape (including ECM harness) and followed them to every point checking for freys, all looks good.
Reseated Spark plug wires
Checked steering column wires for freys, looked fine
Reseated all relays (some of them get kind of warm when car is on, but that is normal?)
Checked coil wire (from coilpack to cap/rotor) and it looked fine, no rubbing or wear was apparent.
*Updates on recent adventures/attempts:
10/06/04*
Put the car on the lift last night, and got out the stethoscope. Had the boss plug the tailpipe with a rag and I listened along the exhaust for leaks. There is a significant one on the weld below the downpipe, but being on the downside of the sensor, that shouldn't affect things?
I put the stethoscope on the downpipe sleeve, and above and below it to see if there is a leak inside of that sleeve in the downpipe, and could hear blowing noises. I then pulled out some kind of sensor I've never used before, which apparently can locate leaks and beeps at you when you run the sensor over one. I forget the name of it.
Anyway, I put it around that sleeve and it beeped like crazy in certain areas, mainly in the gaps at the top of the sleeve, where air could theoretically be pushed out of the downpipe, and funnel through that gap.
Like I mention down below, when driving, especially upon acceleration, I can hear a wind on metal sounding noise below the car seemingly where the downpipe is.
Is this worth investigating further, and worth replacing the downpipe? Could a leak there cause this lean/rich mixture problem and make the car backfire and buck?
*10/07/04*
During lunch today I worked on my car a little. As of late (started last week) every once in a great while, when I start up the car there is a high pitched bzzzz coming from inside the engine compartment, and then it stops. Sometimes it lasts about 5 seconds, but usually (like today) it lasts about 1 second then stops, and I can't get it to do it again without turning off the car, then turn it back on.
I know about the throttle body, and how it buzzes when you first turn the key on, but this is much different, much louder and un-wanted sounding. Plus it only does it immediately after the engine turns on.
Sometimes (like when it was raining last week) it is very loud, and lasts longer. But today, (nice and warm/dry) it only did it very briefly, and not as loud.
I think this may be connected to something...
On another point, I noticed at lunch today when I had the hood open and engine running, was I thought for a while there that I might have a bad engine or transmission mount, which might be causing the bucking. I've pretty much ruled that out because of the following:
With the engine running, I gave the car gas from within the engine bay. I revved the engine up, and tried maintaining a constant RPM while listening to the engine.
And guess what happened...
The engine randomly spittered and sputtered, and the rpm's randomly raised and lowered, even though I held a constant torque on the throttle cable.
I then gave it quick bursts of gas from no throttle to half, then no throttle to full, and the car burped and backfired, and had a slow response.
Perhaps these two incidents are connected?

*10/08/04*
I found out my boss has a good test unit MAF, so last night I pulled out my old, disconnected the negative on the battery and put it in. Waited 15 minutes, then reconnected the battery. Waited 3 minutes, then started the car. I let the car idle for 3 minutes, then took it for a spin. The car definetly pulls harder and felt much more powerful, especially in the low rpm range.
Once the engine was warmed up, I pushed it hard (4,500rpm-5000rpm) to see how it acted. It felt very good, not *as much bucking, but I'm not going to say it disappeared, because it normally doesn't buck in high rpm's as bad as low 1000rpms-3000rpms.
I took it up to about 80mph and everything felt better. I did notice there was a sulphur smell coming from the exhaust, but this was when I was running the engine hard, and I believe it would smell a tad sulphury under these conditions anyway.
I'm not going to draw any conclusions until this coming Monday, because my boss told me I could leave it in over the weekend.
It's been raining on and off here, so this will be a good test for it.
I will keep you all updated.

*10/09*
Has been raining steadily. Car significantly makes the tinking noise less in the rain, and seems to be pulling better throughout all RPM's.
The shutter/stutter remains, although it seems to be less.
I'm not sure if the new MAF has done anything at all, so I will keep you posted.

*10/10*
No changes.

*10/11*
I pulled off the MAF connector while the car was running, and didn't get a CEL light to come on. When I pulled the connector off, the cars idle just dipped, then went back up. I put the connector back on and the car didn't act different at all.
Is it strange the CEL didn't come on when the MAF was completely unplugged?
Anyway, car still stinks, still bucks, tinks slightly less, pulls slightly harder, but there is still a bucking/misfiring problem, and still randomly loses power subtlely.
At lunch today, I turned the car on, and took out the rainguard, so I could access the ECM and it's harness. With the harness plastic off, I wiggled each and every wire going to the computer, and listened for _any_ changes, but could hear or see nothing different. I also traced every wire solder connection going to the ECU and wiggled each accordingly, with no change in engine noise/rpm's etc.
I wiggled the ground connections to the coilpack and the wire going from coilpack to the cap/rotor, no changes. (the ground connections on the coilpack were removed and clean prior to this)

*10/12*
Drove the car to work this morning (was a warm dry night) and the car started up after about 3-4 cranks like always. As it was idling there was the ever present tink tink tink coming from the inside of the intake manifold.
Anyway I drove it to work, and the car ran with more power and better pull with "less" bucking problems. It seems to over all run better on dry warm days. There was significantly less sulphur smell and misfiring today, the car just seemed much smoother, and the stupid rattle in the exhaust was almost completely gone. It's funny how the rattle comes and goes. I believe I sourced the rattle to be coming from the downpipe, and at certain RPM's it just buzzes like crazy. But like I said this morning the car was running better and the buzzing was almost gone.
On cold days especially in the morning there is alot more of a stink from the exhaust, and the car seems to be choking for air, and very unsmooth, restricted somehow.
I heard no buzzing from the engine bay this morning, or last night, which I thought might be the cap/rotor distributor malfunctioning?
Anyway the backfiring was extremely reduced this morning too.
The car *always runs better when it is let to sit for 1/2 hour - 3-4 hours if it is a warm day. But if its a cold day and I let it sit after driving it, it runs like crap after letting it sit only 1-2 hours. But again like I said, if it's a nice day, I can let it sit for all the way up to 5 hours and it will start up and drive smoother.
The bucking is always there, but the car intermittently runs better.
*10/13*
No changes
*10/14*
Took spark plug boots off today and took out all of my spark plugs. They all are very white looking on the ceramic. They are about 1 1/2 months old, and I was assume by now they have been in the vehicle long enough to show me how the car is running.
The plugs are Bosch Silvers
I have used NGK's, no difference on my problem.
Since the plugs are so white, I can assume the car is on the average running too lean...
*10/15*
I'm confirming the gas I use is not the culprit. I always use Chevron Supreme, but today I filled half the tank (tank was on empty) with Shell Regular unleaded.
Just making sure the octane in the Chevron is high octane like it says it is.
As soon as the Shell gas is ran through my system, I'm going to fill half way with Shell Supreme, and see if there's any differences.
Besides changing up the gas I use, I'm going to further research on the vortex the whole running lean syndrome.
I'll keep you all updated.
-------------------------------------------
Anyone that feels my pain regarding Jetta/Golf III's that stink like sulphur, backfire excessively, buck wildly when trying to maintain speeds and/or letting off the accelerator and press it again, have that crazy idle that jumps up and down, PLEASE help me
I will copy/paste the latest post concerning my problem
Posted at the Bentley Publishers website in the tech discussion forum...
DTC Code 16486 P0102 035
Mass or Volume Air Flow Circ.
Low Input
sporadic DTC
96 Jetta Bucks, Stutters, 'nStinks 
Posted: Oct 5, 2004 7:19 PM
"96 Jetta GL with 115,000 miles.
This problem has been looked at and worked on by alot of technicians and mechanics, but no one can figure out the problem. And I've spent alot of money trying to fix it. So before I spend more money, I would like your guys' suggestions on what to do next..
The car sporadically (but 85% of the time) seemingly runs in limp mode, and stutters bad when trying to maintain a constant speed, or letting off the gas and gently pressing it again.
Almost all of the time (which is when I think it runs in limp mode) the exhaust stinks horribly of sulphur smell.
I took the car to the dealership, and the tech put a VAG on it and pulled no codes. I told him how it acted, and that I knew of a large crack in the exhaust manifold (which I thought could be messing with the 02 sensors readings.) He agreed I should replace it, and see if that helps.
It was replaced, and made no difference.
The o2 sensor was replaced before this and that made no difference. Also replaced was the throttle body, coolant sensor, mass air flow sensor (I bought a slightly used one with low miles on it, but didn't change the problem at all) fuel filter was changed, cap/rotor, spark plugs/wires, and catylytic converter (the old one sounded like a golf ball was lodged inside of it when I shook it)
I assume the backpressure from too much gas trying to be forced through the cat-converter ruined the old one, and is making the new one stink horribly.
I have a very annoying rattle as well, which appears to be coming from the downpipe, where there is a metal sleeve, that apparently has been welded many a time.
Recently I took the car to another mechanic with a VAG, and he pulled DTC Code 16486 (P0102), then he cleared it, ran the car, and pulled it again several times.
He suggested getting a new mass air flow sensor, which I had already done just a month before.
I sprayed my coilpack and distributor cap and plugs at night witha spray bottle, and the car didn't act any different (was trying to look for an arc)
The car runs better in good weather 70-80 degrees and dry, but never dies, even when it's wet outside, so I haven't bought a new coilpack yet because I don't think that's the problem..
I'm not sure at this point if there actually is a sporadic low voltage problem, or if there is another problem causing it.
I've cleaned and reseated every single ground and wire connection in the engine bay, including electrical points.
The cap and rotors that I buy (which are bosch) have carbon buildup within 2-3 weeks after putting them on. Also, the spark plugs instantly get a burnt yellow look to them just as fast as well.
I checked my intake boot for leaks, and all other vaccuum line for leaks, and could find nothing wrong. I also traced the ECM harness, cleaned the points and unwrapped all the wiring and traced it all around the engine compartment and found no signs of wire frey or wear.
At one point at mechanic shop I now currently work at (just started last week as apprentice mechanic) the mechanic said he pulled low voltage readings to the mass air flow so that was confirmed, but it still doesn't tell me what is causing it.
When I'm driving the car it "seems" like I can hear a kind of air on metal "wooshing" sound from where it seems to be coming from at the downpipe, like a raspy air blowing noise. Even if there was a large leak there, I don't know if it would screw up the o2 sensor enough to do this.
I've had the run around by every mechanic I've met and have spent alot of money.
At this point I'm thinking either
1. There is a significant leak in the downpipe, making the o2 sensor get a bad air/fuel mixture reading.
2. I have a faulty ECM
3. Hall sender
4. Crank position sensor
5. Fuel pump relay / fuel injectors.
6. Bad wiring somewhere
7. Transmission / motor mount

ANY info anyone might have is truly appreciated, I am at the end of my ropes with this car, and I love the car alot, and really want to get it fixed.
If anyone needs more info on what I've done, please ask me and I will reply quickly..
Thanks in advance,
Casey"
I cannot afford to buy an ECM, downpipe, etc. right now without knowing that it is the cause of these problems. I'm currently working 2 jobs to support myself, and my jetta is my daily driver, and I really have an attachment to it.
It seriously kills me to drive it when I know that I am most likely ruining parts on it.
Any and all info is welcome http://****************.com/smile/emthup.gif 
thanks,
Casey
Brookings, Oregon


_Modified by SpeedRacer20 at 11:45 PM 10-15-2004_


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## bearing01 (May 27, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

Casey... sounds like you're working 2 jobs to support your car. Keep going and you'll soon have a new car!
The sulphur smell & stink I am assuming is because the car is running rich. This will kill your cat with time. Anyhow, if the exhaust manifold has a leak in it I'm not sure how this would affect the O2 sensor. If O2 was to get drawn in and hit the O2 sensor then this would cause the car to run rich. Are the spark plugs covered in soot? This is one sign that the car is running rich. Does the car accellerate ok when wide open throttle? Or idle ok when you take your foot off the gas to slow down? but sputters when crusing? I'd suggest plugging any holes in the exhaust manifold with JB-Weld or something to see if that stops your problem.
You could also check the resistance across the coolant temperature sensor just to make sure it is working. Should get 5 or 6 kOhms when cold and a few hundred ohms when warmed up. If the plug / connector for this guy had a lose connection it could cause the ECM to go into limp-home mode.
Something else that may not cost all that much but are good checks are to check the fuel pressure in the rail. If pressure is too high then this may be contributing to running rich. Fuel pressure regulator or its vacuum may be at fault.
Good Luck


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## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (bearing01)*


_Quote, originally posted by *bearing01* »_
Casey... sounds like you're working 2 jobs to support your car. Keep going and you'll soon have a new car!
The sulphur smell & stink I am assuming is because the car is running rich. This will kill your cat with time. Anyhow, if the exhaust manifold has a leak in it I'm not sure how this would affect the O2 sensor. If O2 was to get drawn in and hit the O2 sensor then this would cause the car to run rich. Are the spark plugs covered in soot? This is one sign that the car is running rich. Does the car accellerate ok when wide open throttle? Or idle ok when you take your foot off the gas to slow down? but sputters when crusing? I'd suggest plugging any holes in the exhaust manifold with JB-Weld or something to see if that stops your problem.
You could also check the resistance across the coolant temperature sensor just to make sure it is working. Should get 5 or 6 kOhms when cold and a few hundred ohms when warmed up. If the plug / connector for this guy had a lose connection it could cause the ECM to go into limp-home mode.
Something else that may not cost all that much but are good checks are to check the fuel pressure in the rail. If pressure is too high then this may be contributing to running rich. Fuel pressure regulator or its vacuum may be at fault.
Good Luck


The exhaust manifold _did_ have a crack in it, but that was replaced. What I'm suspecting has a leak is the downpipe i.e. the piping from the exhaust manifold to the catylytic converter, which could have cracked from the back pressure of the exhaust not leaving the cat once it was ruined and clogged.
At this point, the catylytic converter is about 2-3 months old, and the exhaust manifold is about 1 month old, but the downpipe has never been replaced. I put a rag over the tailpipe and found a large leak after the cat, and what sounded like a leak in that downpipe. But again, we don't know for sure if that would screw up the o2 reading or not.
My biggest lead is that buzzing sound upon startup (which I posted in my update on my original post)
To answer your questions bearing.
1. I checked the spark plugs last night(have only been in there a month, and they looked alright. But my old ones were very yellow and black looking.
2. The car accelerates fine if you are gassing it at wide open throttle. It doesn't jerk and buck when I'm gassing it, or even gassing it hard. It's maintaining speeds and coasting that it bucks and back fires horribly. When the car is running good, I have tons more power all through the RPM range, and taking off from complete stops is extremely easier.
The only thing that is wrong when I'm gassing it or at WOT when it is running bad is I lose power, and the car isn't smooth.
If I was to say, tap the gas when coasting, that would antagonize it in to bucking terribly. I have to be extremely smooth and easy with the accelerator to minimize bucking and backfire. I cannot reduce RPM's under 2k in 2nd gear and coast to a stop, I have to throw in the clutch, or I'm in for a wild ride.
3. The coolant temp sensor is brand new, and I've wiggled the connector on it, and didn't notice anything, but then again I don't know if I would. I have a voltmeter, but am a complete novice at using it. I will perform these tests if you could give me a run through on how to use it.
4. I checked the hose coming out of the fuel pressure regulator, and reseated it. It is nice and snug coming from the fpr, and going in to the intake manifold. I also took out the fpr, and didn't see anything visually wrong with it.
One thing I noticed at lunch today when I had the hood open and engine running, was I thought for a while there that I might have a bad engine or transmission mount, which might be causing the bucking. I've pretty much ruled that out because of the following:
With the engine running, I gave the car gas from within the engine bay. I revved the engine up, and tried maintaining a constant RPM while listening to the engine.
And guess what happened...
The engine randomly spittered and sputtered, and the rpm's randomly raised and lowered, even though I held a constant torque on the throttle cable.
I then gave it quick bursts of gas from no throttle to half, then no throttle to full, and the car burped and backfired, and had a slow response...
By the way, big thanks for responding to my situation, it's hard to find people interested. Not even my boss wants to get involved with fixing it, and he runs and owns the european mechanics shop I work at










_Modified by SpeedRacer20 at 9:53 PM 10-7-2004_


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## twoconnguy (Jan 1, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

Sounds like what my '96 was doing for a while too, and I couldn't find it either. Mine would act up when it was cold and wet...fine in summer rain storm or below 20 degrees. A good local shop finally found out it was a cracked coil. You couldn't really ever see it arcing at night and it would check out fine in a nice dry heated shop. The misfiring it caused eventually took out my O2's and cat, so I thought that was the problem until the next cold rainy day came up, and back to the same problem. I know the coils aren't cheap, but you might try one from a boneyard that guarantees their parts to see if that helps.
Good luck!!


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## bearing01 (May 27, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (twoconnguy)*

I don't like to suggest people to start (blindly) replacing parts on their car that are 100's of $. If you can find a buddy with a similar car or a scrap yard you could swap in parts to troubleshoot the problem.
Because the problem is sporadic it may be a lose wire or something of that nature. I was wondering if it is a problem related to the car operating in closed loop (when O2 sensors + Coolant temp sensor + rpm sensor + MAF sensor + throttle position sensor all tell the ECM how to adjust the air-fuel ratio to 14.7:1). When you open the throttle wide open or start the car at cold the car is not running in closed loop. If this was a problem that occurred only in closed loop then I would troubleshoot / checkout each one of the sensors. They may work when you measure them but a lose connection or bad ground may cause one of them to go dead and trigger a limp-home mode. 
If your coolant sensor had a lose connection then the needle on your instrument cluster would fall to cold or not go all the way to the middle when warm.
Check the connections on your MAF & make sure it is working properly. Swap it out with a friend with a vw like yours if you can. If you replaced it already with one that wasn't new then the second-hand one may also be broken. Make sure there are no lose connections to it. Having said that, if the MAF was to go dead it should definitely trigger the CEL and go into limp home mode.
During your loss of power time do you get a check engine light? There may be codes stored even if you don't get a CEL. 
If the problem occurs during both closed loop and open loop (cold starting or WOT) then my next step would be to go through your ignition system. What spark plugs are you using? I've heard mixed suggestions wrt plugs. Bosch Platinum's vs copper or silver. One time I had a problem where only up hills and WOT would the car sputter & misfire. It was either damaged plug wires or the car didn't like the platinum's. I replaced the plug wires with the OEM ones ($100) and used FR8DC ($1/ea) and the car worked fine after that. From above, I read that you changed the plug wires but not to Bosch/OEM. I have heard mixed reviews of people doing that and the high-performance plug wires (non-oem ones) gave them troubles.
If you can't find a friend that has a VAG-COM then I suggest you consider it as an investment. If you already have a computer or laptop then it will cost around $300. The program will allow you to look into the operation of all the sensors and stored codes. This tool would be very useful in your case right now... it would let you see exactly what's going wrong.


_Modified by bearing01 at 1:05 AM 10-8-2004_


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## FL 2.0L (Aug 1, 2002)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (twoconnguy)*


_Quote, originally posted by *twoconnguy* »_Sounds like what my '96 was doing for a while too, and I couldn't find it either. Mine would act up when it was cold and wet...fine in summer rain storm or below 20 degrees. A good local shop finally found out it was a cracked coil. You couldn't really ever see it arcing at night and it would check out fine in a nice dry heated shop. The misfiring it caused eventually took out my O2's and cat, so I thought that was the problem until the next cold rainy day came up, and back to the same problem. I know the coils aren't cheap, but you might try one from a boneyard that guarantees their parts to see if that helps.
Good luck!!

I had the same prob. Got it done before the sensors and cat got involved. I'd suggest a swap of the coil again. Good luck!


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## Flintstone (Jan 9, 2003)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (surferfletch)*


_Quote, originally posted by *surferfletch* »_
I had the same prob. Got it done before the sensors and cat got involved. I'd suggest a swap of the coil again. Good luck!

I agree the coil is a very common problem. Also check that the wiring harness from the coil to the distributor is in good condition.Sometimes the wires get rubbed through and cause the car to run like crap. That happened to my car. Good luck!


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## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (Flintstone)*

My first post on this thread has been updated under *10/08*
Blue ignitor wires thoroughly checked. These are very good German built (not alleged super high performance crap)
My coilpack is original and has been misted excessively with spray bottle to antagonize it into running poorly, but the car ran *fine* and the idle did not change or sputter at all.
Note:
*I will update DAILY until my problem is solved. The updates will be posted under my original post at the top of this thread.
I Know alot of people out there are having this problem, and I'm damn commited to fix it and try to help everyone out there cuz I feel your pain* http://****************.com/smile/emthup.gif


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## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

*First post updated 10/09*


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## Sam Ontario (Aug 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

Bad sulfur smell is almost sure caused by exhaust leakage.
You have done everything on wires and plugs. Check your alternator brushes and rectifying parts. You might have these parts dying.


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## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (Sam Ontario)*

*First post updated 10/11*


_Quote, originally posted by *Sam Ontario* »_Bad sulfur smell is almost sure caused by exhaust leakage.
You have done everything on wires and plugs. Check your alternator brushes and rectifying parts. You might have these parts dying.

Sam, do you think fixing these exhaust leaks (namely, the downpipe) would be a good investment in time/money in this effort? Could it be the cause not just a side effect of the main problem?
Let me share a thought I'm having...
When I first bought the car, it seemed to run fine (was a year ago)
I never noticed bucking/misfiring, sulphur smell or anything. Then I installed my stereo when I got home, which consists of:
Alpine 400watt amp
12'' Cerwin vega 900watt sub
Pioneer Deck
And the vw premium audio package that came with the car.
I wont say "since then" I've had the problem, but it may possibly be a good lead...
If in fact my stereo killed my alternator, could a failing alternator cause this problem? Now in response to that, I took the car to a shop and had them test the alternator, and they said it was fine. But on the other hand, these guys are a tire/alignment shop, and they may not entirely be accurate...
Continuing on my suggestion...
Before my Jetta, I owned a Mazda 626, with the same stereo I have now. I went through a battery and alternator fairly quick with that car, and I had problems with it holding a charge. But seemingly it never bucked or misfired... Did the stereo kill the alternator is the question I'm getting to...
Another idea...
Before the Mazda 626, I had an 87 VW Golf, with the *same stereo* With the golf, I had very similar problems, the car would BUCK VERY BADLY, much worse than my Jetta. And it would happen upon accelleration. I never replaced the battery or alternator on that car, as it was my first car and I was no where near as experienced with mechanics as I am now.
But the fact was it bucked, and hesitated.
On the same note, my stereo seems to sporadically lose "umph" and just get kind of punchless if you follow me. The AMP/Sub used to REALLY pack a punch, and over the past year, has seemingly lost power. When I first installed it, the AMP power settings were turned very low, and it was still very loud.
Now if I was to go to my car and play the cdplayer with the AMP settings turned ALL the way up, it's not even as loud as it used to be with them all the way DOWN! The subwoofer also makes a scratching noise when it is hitting hard, and it never used to do that.
One other thing is, when I hit the power on my cd player with the car on OR off, it takes about 5 seconds for the sub to turn on, but the cd player is already playing the music, and the stock speakers are playing along too, but the sub takes 5 seconds, and then makes a BOOMP noise then it works just fine (albeit, low powered)
Sometimes though, and I'm talking like 5% of the time, the subwoofer/amp come on EXACTLY the same time I hit the power button on the cdplayer, like it is supposed to.
WEIRD??? And possibly connected to my problem?
Connected to the failing voltage regulator or alternator?
Perhaps...
The cd players power is connected straight to my battery, I bypassed the factory wires, and wired it straight to the POS+ on my battery. The ground on the cd player is connected directly to my NEG- post on my battery as well.
As for the AMP, the power from it (amp is in the trunk) goes straight to the batteries POS+ post (it does have a fuse on the amp power line don't worry...) and the ground on the amp goes to the trunk latch connector, which was the paint was scratched off of , and seemingly to me was made in to a good ground.
All of the connections on the stereo, and the power/ground wires on the amp and stereo were all double checked, and every thing looks fine.
Does anyone think this problem could be associated with my car misfire problem?
If I confused anyone here just let me know and I will clarify http://****************.com/smile/emthup.gif 


_Modified by SpeedRacer20 at 9:40 PM 10-11-2004_


----------



## Sam Ontario (Aug 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

I supposed you have a 90Amp alternator. You should be fine if thats the case.
If the mechanics had checked OK then it should be fine except if there is intermittent fault in the rectifying circuit. But if you suspect its the amp, why not take the amp off (all wire connections) and see if things get better.


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (Sam Ontario)*

I completely removed the Cdplayer and amp from the car, with no change. If the damage from the amp to the alternator/regulator etc has already been done, removing the cd player /amp wouldn't change things now, I'm thinking


----------



## Sam Ontario (Aug 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

Your alternator may not be a problem. Just think and re-check whatever you have done to the car. I am not a mechanic but I like to get my hands on my little Golf and whatever I have done anything to the car to improve, I always break some other things b/c I am not a mechanic.
Sorry I did not read all your posts concerning your car problems. Perhaps you would like to describe your car symptoms more. If your idling is OK, then at what gear, what mph, at what revs range, at what oil temp etc. at what weather conditions you have the mysterious stutter problems, so that someone reading your post may have a clue to your problems.


----------



## Sam Ontario (Aug 12, 2004)

Since your engine has intermittent stutter, if you have checked all loose wirings as suggest by someone above, you may like to try to put extra earthing onto the instrument wirings, especially those near Coil, Spark Wires. This extra earthing should spiral around the instrument wires with both end secured to metal parts of the car. Put in shielding on your ecm. Check your spark wires not to cross or contact each other. You can also earth the car body to discharge all electrostatic charges to ground (required to drive at least an hour to break in a new electrostatic band).
Good luck!


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (Sam Ontario)*

*First post updated 10/12*
The bucking is in all RPM's Sam, on warm/cold/rainy days, but lessens in high RPM's, and is more apparent in low RPM's in a high gear, or trying to maintain a constant speed in 1st gear.
It also seems to lessen in warm dry weather, and when it is left to set turned off for a while.
The car always makes a raspy air sucking noise, kind of like the noise Darth Vader makes when he's breathing but slightly higher pitched








Car backfires excessively on downshifting and deacceleration.
I always am feathering the throttle and throwing in the clutch very quick and smooth when slowing down or the bucking gets severe.


----------



## Busbodger (Jul 28, 2004)

*Re: (SpeedRacer20)*

Vaccum leak?


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

Unless the intake manifold has a leak, yes I have already checked vacuum lines, and found no problems.
Air intake boot doesn't have any cracks, the PCV hose is new and the PCV reservoir and that little fitting (that plugs in to the air intake boot) seems all fine as well. PCV reservoir was cleaned and had tons of gunk in it.
The throttle body is new, new gasquet as well, and all the bolts holding it on to the manifold were checked.
Unless there is a leak actually on the intake manifold or there is a bad gasquet, I can't think of any other places to check for leaks.
The only leak I actually know of is a leak in the downpipe, and a leak just after the cat converter.
I checked emission line that goes to the air intake box to the manifold, and also checked the ATC line that connects from the top of the air intake box to the bottom (controls the ATC flap in the box)
Checked the line from the intake manifold to the fuel pressure regulator, looked good. FPR is not clogged visually either.


----------



## Busbodger (Jul 28, 2004)

*Re: (SpeedRacer20)*

Injector seal leaks?


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

Haven't checked that yet, will try tonight. Although I don't know if a leak in an injector seal would cause intermittent problems...? Perhaps if the electrical to the injector sporadically cut in and out. But the car just randomly misfires.
Anyone else think it could be an injector o-ring or faulty injector?


----------



## Sam Ontario (Aug 12, 2004)

*Re: (SpeedRacer20)*

Oil pump discharge pressure checked? If its tinking, metal loosen? broken piston ring? I am just guessing.


----------



## Busbodger (Jul 28, 2004)

*Re: (Sam Ontario)*

Have you checked the engine with a vacuum gauge/compression tester/leakdown tester? 
Just to ensure the problem is electrical and not mechanical.


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*


_Quote, originally posted by *Busbodger* »_Have you checked the engine with a vacuum gauge/compression tester/leakdown tester? 
Just to ensure the problem is electrical and not mechanical. 

No but I will get that done this week. Hopefully my boss will have all of the correct tools to perform these tests..
*I will check:*
Fuel Injectors / seals
vacuum test
leakdown test
compression test
If anyone knows how each of these tests are ran, I'd appreciate learning, though I'm sure my boss will know, I'd like to get a little info on them before I go to the shop tonight.


----------



## Busbodger (Jul 28, 2004)

*Re: (SpeedRacer20)*

Any repair manual for any car will explain how to run these tests. Check your library if you don't have a manual. The procedure for the tests will be the same no matter what brand the engine is so if you do not have a manual, can't afford it, go to the library and look up how to do this to a Ford or a Chevy.
Sears has all the tools as do many of the FLAPS. All of the tests reveal similar information so they might be redundant from a certain perspective. I suggested all of them so that you can choose what you want to do based on your available tools. 
I usually do compression tests and vaccum tests. The vaccum test is as easy as connection the gauge to the engine at a vaccum source. The compression test is as easy as removing the spark plugs and screwing the tester in each cylinder in place of the spark plug and then crnaking the engine for 30 seconds or until the gauge tops out. Record the readings and then compare the numbers. You should have no more than 10% difference in pressures in any of the cylinders. Your Bentley ought to tell you the target pressure. 
Stock cam in that engine? 
A leakdown test is basically a modified compression tester. More information (specific info) can be gathered about the condition of the piston rings and valves. 
Maybe you've got a burned valve... 
C
http://www.cruzers.com/~twakem...n.htm
http://www.morrisminoroc.co.uk....html
http://www.se7ens.net/faq/7faq.htm
6.6. How do I perform a leak-down test?
This message was posted by Kiyoshi Hamai <[email protected]> to the lotus-cars mailing list, and is reproduced with his permission:
It's really pretty simple to build your own leak down compression tester...
The tricky part is getting an adapter that will screw into the spark plug
hole. It sounds like the hose compression tester you now have, assuming it
is a screw in type, will work. So, using that hose, attach a air pressure
gauge (0-150psi) and to this a means of attaching it to a air compressor.
Do put a quick release coupling between the gauge and the air source. Also
you'll need a valve between the gauge and the air supply. On the one I made
I adapted an old air blower nozzle to use as a valve. Your air source
should supply at least 100 psi. At sea level atmospheric pressure is about
14.7 psi, so 8:1 compression would be 118 psi. Once you've filled the
cylinder with air you want to cut off the supply of air so you can observe
the rate the air in the cylinder leaks out.

Now, rotate the engine so that the cylinder you're testing is in the
compression stroke (both valves closed). Replace the spark plug with your
tester, fill the cylinder with air (100+ psi) and watch the gauge and
listen. Here's the typical things you'll see...
1) Gauge falls slowly, no audible hisses - this is normal and GOOD!
2) Gauge falls fairly quickly, no audible hisses, no bubbles in the
radiator - rings maybe worn
3) Gauge falls fairly quickly, no audible hisses, bubbles in the radiator
- blown head gasket
4) Gauge falls quickly, no audible hisses - worn valve or valve seat
5) Gauge falls quickly, audible hiss - burnt or leaking valve, listen to
carb/intake or exhaust to isolate intake or exhaust valve...
6) Gauge never registers any pressure!!! BIG PROBLEM! Bent valve, holed
piston, holed cylinder, etc.
> I have an engine that has 50 psi difference between the best and worst
cylinder.

Some will say this is not much, but I'm of the school that 50 psi is
significant, down 25-35%. A leak down test will help you pin point the
cause. If there's lots of mileage on the engine it could either be valves
or rings. If head is fairly fresh and lots of miles, then it's more likely
rings.
http://www.240sx.org/faq/artic...t.htm


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

Yes stock cam.
I have the Bentley, will look in to it.
I'll do the compression check and the vacuum test this week, possibly tonight, and let you guys all know how that went.
I'm also going to check my plugs to see if one of them looks burnt and try to find if and which isn't getting a spark.
I appreciate all the info and will keep you informed.


----------



## towhook (Oct 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

I fee~~EEL your pa-a-ain. New to the forum and new to my 97 Jetta GLS. It too has the bucking, hesitating, poor idle condition I've learned so many of us seem to have. I've also replaced the standard array of parts (ECU, MAF, Fuel Pump/Filter, Plugs, Wires, Coil, TB Cleaned).
Got a referral to a mechanic that specializes in these hard to diagnose problems...so...we'll see if he can find it. I've read many many posts on several sites about this problem and one thing is clear. Speedracer20 said it perfectly...there seem to be a hundred different solutions to this problem. Well..I've compiled a list of solutions, all of them had symptoms of hesitation during driving, ran worse warm than cold, idle badly, bucking:
here's the list....some of these fixes were more common than others..
1) Fuel Pump Relay (at least 2)
2) Plug Wires (many folks)
3) Purge Valve (1 fix)
4) Vacuum lines (surprisingly..only a couple)
5) Hall Sensor (at least 2)
6) Gas Cap (1 fix...good one...no pressure in tank)
7) O rings on Injectors (several folks)
8) MAF Sensor (several)
9) Plugs (quite a few..lots of negatives about Bosch Plat's +4)
10) Engine Speed Sensor (2 fixes)
11) Wires to Battery worn due to loose engine mounts (huh...1 bucker stopped by this fix...hmmm)
12) EGR/ICV/ISV : not our problem..don't have these parts...
13) TPS (many TB cleaned and replaced...only 1 said fixed prob)
My Jetta doesn't have a Fuel Pump Relay....not sure if it ever did...checked it to find it missing..so I'll be installing one...but don't think this is the problem.
Hope to hear something from the mechanic tommorrow...hope this guy is as good as they say...cuz' I'm stumped more now after reading these posts







I'll keep ya posted.


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## Sam Ontario (Aug 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (towhook)*


_Quote, originally posted by *towhook* »_9) Plugs (quite a few..lots of negatives about Bosch Plat's +4)


Bosch Platinum+2 plugs are equally bad. Stick with copper plugs and gap them precisely.


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (towhook)*

I purchased a ECM power relay from techtonicstuning, and went to put it in to the surprise of no existing one installed.
I read some of the Jettas don't have them.
It fit successfully in I believe slot 3 (going from left to right, top to bottom) but changed absolutely nothing.
The hole in my downpipe makes a loud air on metal woosh noise especially on acceleration. Why is it I keep coming back to the exhaust?
My exhaust manifold was replaced because of a 3 inch or so crack in it... from back pressure obviously? But why so much back pressure? Clogged cat? Why was the cat clogged in the first place?
Did the hole accumulate in the downpipe first, then throw off the o2 sensors, thus making the car see there's not enough air, thus leaning the mixture. Then the car thinks it's too lean somehow and makes it too rich, thus clogging the cat, thus cracking the downpipe worse, and creating a monster crack in the exhaust manifold???
ARGH! If I knew what went wrong originally and what caused what, I could fix this crap.








BTW Towhook, keep us updated on the new mechanic


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

*First post updated 10/14*
Took all of my spark plugs out today at lunch, and they are all very white looking, and they all are identical in their wear.
This I assume is from my car normally running too rich, which is strange because my tailpipe tip is covered in black rust/soot, and the exhaust fumes stink like sulphur.
This is strange because I always assumed my car was running rich...
It's strange, the car when just sitting and idling, the exhaust smells nothing like sulphur, but it doesn't smell "right"...
But when I'm driving, and especially driving the car hard, the exhaust smells like rotten eggs/sulphury smell.
The exhaust never just smells like gas, like a normal cars exhaust would smell.
It seems like the car runs intermittently rich/lean..


_Modified by SpeedRacer20 at 10:25 PM 10-14-2004_


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

*First post updated 10/15*
Trying different gas brands and octanes...
Since my spark plugs are completely white, I'm going to further research problems with running lean.
Will keep you all updated.


----------



## Sam Ontario (Aug 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

Bad smell must come from your leaky exhaust pipes. Did you check fuel rail pressures for lean mixtures?


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (Sam Ontario)*

The smell changes from a sulphury smell, to a weird smell I can't explain.
I would assume the car over compensates sometimes and really riches out the mixture, and that is the sulphur smell. But when the car is just sitting after driving it and idling, it has a very odd smell, which I also assume is when it is running lean.
But when I first start up my car, _sometimes_ it smells fine, like normal gassy smell.
Sam, the smell is coming from the tailpipe on my exhaust definetly. What I'm trying to figure out concerning the downpipe, is if it is throwing off or ruining my o2 sensor, and making the cars air/fuel mixture incorrect.
Thanks for the replies http://****************.com/smile/emthup.gif


----------



## towhook (Oct 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

Well...took the mechanic a few days but he's pinpointed my problem to be my catalytic converter. He claims that the one that is installed, which is fairly new (was installed last year by previous owner) is a "generic" cat and
not made for the Jetta. So...it has gone bad and the packing is clogging the cat. According to this mechanic since my problems with hesitation and bogging only occur when the car is warmed up, that includes poor idle and while driving, the heat causes the cat clog to be more apparent. He removed he cat completely and ran the car and says it runs great without it. So..I'm having a new OEM cat installed today...and hope to get the car back tonight. I'll let you guys know if I have the same results as the mechanic is claiming. I sure hope he's right....that bog is a real pain.


----------



## towhook (Oct 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (towhook)*

Are Jettas know to have fuel mixture problems?
The more I think of my cat being the cause of my bogging..the more I believe it's not the cat..but whatever caused the cat to fail. So...even if my problem is solved...it may return.
I didn't mention in my last post that I also had the fuel injectors cleaned and the TPS reprogrammed. Mechanic got the TPS bad code (I'll get the code # when I pick up the car) This was done first..but car still ran bad...which led to him finding the bad cat. Up until the mechanic found the cat...he kept telling me it's running great....you just can't drive it anywhere.








Well..it's noon now and I sure am getting anxious to drive the car. Wish the shop would call. I've thought about this problem so much I'm not going to be able to let it go even if the car runs fine. I've seen so many "fixes" to this problem and seldom seen the bad cat as a cause (rather an effect). 
Oh...I called my local VW dealer to find out about getting the code to the security system/radio and they said I have to leave the car with them overnight so they can check it just in case I don't have another problem causing the security system to need reset. WHAT??? Does this make sense to you guys?? Is this what I have to do? Granted..it's not a big deal..but I thought I could just give them the serial on the radio, prove I own the car, and they'd tell me my code. They want to charge me for doing this "work". Geez...seems odd. Anyone else have to do this?


----------



## Busbodger (Jul 28, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (towhook)*

B.S. they do NOT need to keep your car overnight... They are trying to milk your wallet. 
Chris


----------



## Busbodger (Jul 28, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (Busbodger)*

IF your car has a problem with the security system, then you will have the code and YOU can reset the radio everytime it screws up (AS IF you have a problem). Tell them you want the code, and if it screws up you'll bring it to them. 
A BUNCH of B.S. they are telling you. 
Chris


----------



## towhook (Oct 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (towhook)*

The shop just called. The car is ready!!
I'll get all the details when I pick up the car..but here is the quick version:
Mechanic claims that reason all the parts failed was because the timing was off over 2 degrees. Excess fuel caused the cat to fail. Found out they also replaced my plugs.
He's going for a test ride now....assuming I don't get a call back from them saying...oops...it's still bogging....I'll have the car by 5 tonight and I'll let you guys know how it runs.
To summarize:
At the point the car entered the shop it had either new or less than 1 year old:
MAF,
Throttle Body
Plugs and Wires
Ignition Coil
ECM
Fuel Relay
Fuel Pump
Fuel Filter
Air Filter
Struts








(fortunately for me..the previous owner did these repairs $$$)
Note..none of the parts above solved the problem (that's why I got
the car 2K below book value..it's a low mileage (87K) black GLS in
perfect condition ('cept for that damn hesitation







)
If the mechanic has solved it...then we've got:
Adjust Timing 
New Plugs
New Catalytic Converter
(Bad timing was the root of my problem..this caused other parts to fail which caused cat to fail..hence it began with minor idle issues, no bogging..to bad idle and bogging getting progressively worse over time (1 year period)).


----------



## towhook (Oct 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (Busbodger)*

Thanks Chris...my son took the car in (he's a Chris too)...he's 19...he figures they gave him the run around. I'm going to take it next time and we'll see what they say to me. I figured it was bull....dealer service guy trying to take advantage of my son.


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (towhook)*

I just recently did my timing, and replaced all parts. There is a possibility I fudged up and got the timing a bit off, but I'm pretty positive I set everything dead on. The misfire was there before I replaced my belts and did the timing so go figure.
One thing I did notice the other day when I was replacing my vacuum hoses, is the coil pack did indeed have a CRACK in it. I was like "AHA!".. I found it extremely odd it had a crack in it, because I've done the mist test so many times and saw no spark, or change in idle behavior, plus I have taken it off 2-3 times before and examined it for cracks.
Well I pulled off the coil and it had a hairline crack about 2 inches long that wrapped around 2 sides of the coil. I'm thinking this has got to be my problem and somehow I overlooked it. I think I overlooked it before (assuming it was there the other times I examined it) because it is so straight it looks like a manufacturer seam.
Anyway, I got some 5 minute ceramic epoxy from Fred Meyers, and did what seemed a very throrough job of covering the crack and did 2 layers of it to boot. waited about 2 hours or longer just to be sure, put the coil back on, reconnected the battery, and drove off.
I don't know if it is a mental thing, but the car seemed to idle alot smoother, didn't do the idle dip, didn't misfire anymore, thought I fixed the problem...
Well I took it on a 4 hour road trip to test it out on the weekend, and it was a SEVERE storm the whole way there and back, so I thought perfect chance to see if the coil was causing misfires when it got moist.
Well it seemed the whole trip the car was completely rid of the unnatural bucking when releasing the gas or maintaining speeds, and it also seemed the car had more power, and felt very smooth.

Until I got about 1/2 hour from home on the way back. The loud tinking noise from the intake mani came back. The idle dipped up and down. The engine just seemed to lose power and make a raspy sound from the downpipe area.
god damnit.
I haven't yet checked to see if my epoxy job failed yet, but I will soon. If indeed it is the coil having a problem, and epoxy will keep failing, I will buy a new one.
I'll keep you all updated.



_Modified by SpeedRacer20 at 6:26 PM 10-19-2004_


----------



## Sam Ontario (Aug 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (towhook)*

Check your O2 sensor outputs if your car is also running at high fuel consumption.


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (Sam Ontario)*

I have a voltmeter but have never used one in my life. Don't know the procedures for checking voltages/grounds/current etc.
Any advise would be good...


----------



## FL 2.0L (Aug 1, 2002)

Coil.


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (surferfletch)*


_Quote, originally posted by *surferfletch* »_Coil.

You think it's the coil?
You *know* it's the coil?
I already epoxy'd it, should I epoxy it again?
If I knew it was the coil, I would just buy another.. but I'm trying to deduct that it is for sure a coil before I buy one. I can't do the swing and miss tactic of buying new parts again.


----------



## Sam Ontario (Aug 12, 2004)

*Re: 1996 OBDII Jetta GL Stutters, putters, tinks & stinks. Technicia ... (SpeedRacer20)*

OBDII should have 2 O2 sensors. The one b4 cat is most important. There are 4 wires on the oxygen sensor. The middle ones are power supply to O2 sensor for heating. If battery supply to the sensor is 12V, u can ignore them. Check the oustanding wire if voltage is between 0.3~0.9V, the sensor is OK. Your voltmeter "+" should be connected to this wire and "-" should connected to the car metals. You do not take the connector off to do the measurement. You need to start the engine during measurement.
Surferfletch has indicated in many occasions about the coil. Ignition Coil should also be checked in accordance with Bentley's procedures. If in doubt, replace it. If its too expensive try aftermarket ones with a little modifications as somebody have suggested.


_Modified by Sam Ontario at 4:04 PM 10-19-2004_


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## FL 2.0L (Aug 1, 2002)

Speedy:
Take a look at this short post...
http://forums.vwvortex.com/zerothread?id=1134581


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (surferfletch)*

I actually read that post quite a while back, and it's my leading reason why I think I should attack the downpipe first. The exhaust manifold had a monster crack in it already, which has been replaced.
I put a sniffer type machine on that sleeve and it beeped madly at me. Plus when accellerating I can hear the air blowing on metal sound.
But I know for a fact there is a decent size crack on my coilpack that may or may not have been completely fixed when I epoxied it...
Thanks for that link I will keep you posted. It may take me a while to get the $$ for the coilpack and downpipe but *will not* forget to post my results.
Thanks again for all the help. http://****************.com/smile/emthup.gif








Casey


_Modified by SpeedRacer20 at 4:07 PM 10-21-2004_


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

Btw regarding the downpipe installation, any tips or tricks I should know before tackling the project? Special tools etc? Gasquets bolts etc..
I have access to a European mechanics shop with a lift (where I work) so that will be no problem.
Thanks


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

Been raining hard, fairly cold, car runs still runs badly.
A couple times a day upon starting the car, there is an unhealthy bzzzzzt noise after the car is started for about, 3-5 seconds, then it goes away.
The idle dip/rise is still there, car will randomly act like it's going to die, then over idle up to 1100rpm's, then stabilize.
Car still misfires every 5 seconds or so while idling.
I'm still working on the funds for a new coil and exhaust manifold.
My theory remains that there is such a big leak in my downpipe, that the o2 sensor sees too much fuel, and leans out the mixture excessively, which is why my spark plugs show the car is running too lean.
I was told by a VW mechanic with 30yrs experience that the car smells like sulphur when it runs *LEAN?*
I've read/been told that means it runs rich... but my plugs are perfectly white, indicating lean... umm someone confirm?
I haven't forgotten about you guys http://****************.com/smile/emthup.gif 


_Modified by SpeedRacer20 at 12:28 AM 10-26-2004_


----------



## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

I feel your pain! I am working on an almost identical problem to your's. The only thing that has ever helped me so far with this problem was temporarily removing the throttle valve housing and cleaning it out with engine degreaser. I then rinsed it off with water, let it dry completely and put it back on. My Jetta ran MUCH better, but after about 2 weeks it started idling rough again and now it is back to running like crap. Hopefully we will sort this mess out.


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

This problem is causing mental issues I think...
Everytime I try something new, and it seems to fix it for a few days up to a week, then bam the car is back to its oldself again. It makes me wonder if it really did anything in the first place...
The few days we "think" the problem is gone, we are wishing and hoping it is gone so much we make it disappear temporarily with our minds


----------



## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

I took off the coil again, and REALLY covered it well with epoxy, just to make sure it got covered properly. Was driving the car today (fairly cold, but no rain) and I was sitting at a road construction area going to work, and could hear my EGR device turning on and off. I'm not quite sure how that thing determines when it should turn on and off, but it's quite loud. At least noticeable from inside the cabin.
I've noticed when the car loses it's constant idle and wants to die (never has died though) that EGR thump thump thump noise gets very loud and then goes back to "normal" when the car reassumes it's normal idle RPM.
Again I didn't even know the EGR made that thump thump noise until lately.
Could it be related to the car wanting to die, and it's bad air/fuel mixture problems, hesitating, bucking, misfiring?
BTW I don't know if the coil was a failing part after all. The epoxy seemed to help at first (like always) but now it backfires and misfires like it always does. BAH


_Modified by SpeedRacer20 at 11:28 PM 10-28-2004_


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## FL 2.0L (Aug 1, 2002)

We need to take up a collection for a coil swap, Speedy!


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## Busbodger (Jul 28, 2004)

*Re: (surferfletch)*

Theya re talking about a '94 on [email protected] Sounds about the same problem... 
<snip>
The O2 sensors are switching fast. I haven't checked the maf yet. 
what is accepatble data for the maf? I assume there is an airflow 
measuring block.
--- In [email protected], [email protected] wrote:
> Have you smoked checked the intake for leaks, If it has an egr 
valve is it 
> partially stuck open, have you monitored the maf for bad data, 
also as some one 
> else said about carbon build up bg 44k works very goog to clean 
carbon. Are 
> the o-2 sensors
> switching fast if you create lean and rich running conditions,also 
the fuel 
> pressure regulator should be checked.
<unsnip>


----------



## Busbodger (Jul 28, 2004)

*Re: (Busbodger)*

Maybe the EGR valve is defective. Block off the port on the head with a scrap of metal. I did this on a VW Bus b/c the EGR valve is NLA. Fixed the engine.
EGR valve is supposed to be open at part throttle only. At idle and full throttle is it supposed to be closed. 
Is the VW EGR valve electric or vaccum?


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

It seems to only turn on (meaning I can hear it) when I'm sitting idling. It will make a slight thump thump thump noise, and then get loud and the thumps farther apart. Sometimes it seems to match when my car suddenly wants to die...
The throttle body has a EGR hose coming off of it, which goes down to a little EGR box thingy, that has an electrical plug hooked in to it. This little EGR thing is what makes the thump thump / tick tick noise and it seemingly does it erratically.
I'm not sure how these things work. I know that the EGR box thing that makes that noise is attached to the side of the air intake box.
I unplugged the line that goes from the little box to the Throttle body, and it intermittently sucks air from inside the TB/Manifold I assume.
Any info regarding this thing is appreciated. I don't know if they are supposed to make this much noise or what..
Um, I don't know if it is vacuum or electronic or both








And like I said, the other day I was sitting idling, and the RPM's dropped all the way down to 400 or so, then up to 600, up and down like 5-6 times, then went up to 1100 rpms, and back down to 900 or so. As this was happening the thumping noise from the EGR got pretty loud... err?
And as far as testing parts goes, I'm a poor man that has an electrical meter, a Bentley, and an undying love for his volkswagen.
I'm not an electrician.
Though I can't drive this car everyday and watch it progressively run worse and worse. I know this problem is ruining other parts as I drive it. IT KILLS ME!










_Modified by SpeedRacer20 at 7:03 PM 10-29-2004_


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## Busbodger (Jul 28, 2004)

*Re: (SpeedRacer20)*

Okay. Time to get out the Bentley. I think you are on to something. 
Try blocking the vaccum line - pinch it off - and see if the engine idles correctly then. It maybe that the vaccum cycles it and there is an electric valve to control that vaccum. 
Maybe this vaccum valve is failing... Anyhow pinching the line will take the EGR out of the equation... 
Chris


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## Busbodger (Jul 28, 2004)

*Re: (Busbodger)*

I had an EGR that was solely vaccum operated on a Honda Accord that displayed weird behavior (surging at steady speed) due to an open valve (stuck open) and an VW Bus that had all sorts of idle problems because it leaked (open) at all speeds. A 3rd car a Lumina had this same problem and would turn on the check engine light and idle slightly poor. 
In the case of the Honda I replaced it. In the case of the VW bus I blocked it off. In case of the Lumina the part was $200 and I let it stay broken (belonged to my grandfather) because he wanted to just sell it to buy a Buick he liked.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

I'll go ahead and check out the EGR test procedure in the Bentley, but I'm pretty sure I'll be coming back on here today for tips on how to do it. If the thing tests bad, or may be the culprit, I wonder if can disconnect the EGR connection from the throttle body without any ill side effects.
I am pretty sure it will throw a CEL, that is what happened when I unplugged the electrical connection on the thing while the car was running.
BTW The idle surge is completely random, and I will probably not notice it has gone away unless I plug that line and run the car for a few hours.
What I DO notice right away is the misfiring while idling.
Could a faulty EGR throw off my air/fuel mixture?
I Just read that most OBDII Jetta's do not have an EGR, they have an air pump connected to a line that goes to the throttle body. The other side of that line goes to a charcoal canister, which can become plugged?
When I removed the cap from the air line, the car tried to die.
I'm afraid to cap off the air line from the TB and bypass the pump, in case it has some kind of sensor sending signals to the ECU..
More info on these things is needed http://****************.com/smile/emthup.gif


_Modified by SpeedRacer20 at 7:45 PM 10-29-2004_


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Like I said before, the problems I am experiencing are IDENTICAL to yours Speedy. I have also been taking a look at that EGR thingy. The part that you are talking about that is connected to the airbox and making the clicking noise is actually NOT an EGR valve, it is an Evaporative Emissions (EVAP) canister purge regulator valve, and it is completely separate from the EGR system. From reading the Bently, it is not clear, but from what I can make of it, SOME 2.0L OBDII Jettas have an EGR system, but not all. However, I know that all Jetta III's (93'-98') have an EVAP system with a purge regulator valve (the thing making the clicking). For a while my EVAP purge valve was also making a loud ticking sound (it was very annoying), and then suddenly one day it stopped. I am not sure, but I think that my rough idle problem began at about the same time that valve stopped ticking, which leads me to belive that the two problems MAY be related. I wonder if maybe it was ticking so loud because it was about to break. Anyways, I am supposed to get a slightly used valve in the mail in a few days along with a used, but working, MAF. I will put these two parts in my car and see if my irradic idle goes away. It is too bad that our cars are not 97' because then they were produced with an EVAP leak detection pump, which would have been very helpful to us. I will post more stuff later.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

Thanks tiohero, keep me informed on the EVAP. Perhaps either the air pump to the EVAP is going out, or the charcoal canister is clogged up. Are you replacing both those parts?
Keep us informed.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Here's some more info on the EVAP system:
http://pg.photos.yahoo.com/ph/...3af,0


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

I don't have a VAG to see if the EVAP is malfunctioning. It does say in those notes that it is responsible for air/fuel mixture, especially at idle... My question now is to test it, should I unplug the line from the TB and plug it up, AND leave the electrical connection to the air pump connected?
Is this electrical harness that goes to that pump just an on/off connection or does it monitor and send sensor signals to the ECU?
Will it hurt anything to cap off the TB and run no EVAP to see if it was the problem..?


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## tiohero (Sep 28, 2004)

Speedy, 
I am not sure how to test it really. My test is going to be replacing it and see what happens. I am almost certain that the EVAP purge solenoid is just a valve that opens and closes. I am relly not sure how the ECU knows when to open and close it. Just to let you know, I also put Valvoline fuel system cleaner in my tank today (the crazy concentrated stuff that you can only use once a year), it cost about $10 for the bottle, but immediately my car started running differently, not really better, but not really worse, I'll let you know if it makes any real difference once I get towards an empty tank.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

Ok, keep us informed.
BTW I've tried that stuff before, didn't make a difference.


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## Busbodger (Jul 28, 2004)

*Re: (SpeedRacer20)*

Do us a favor and replace the MAF and the EVAP parts 1 at a time so we can tell what made the difference... 
My MKIII Cabrio is idling roughly now - not so rough it wants to stall, just enough to irrate me... 
Going to replace the dist cap and rotor (106K miles), got new spark plugs and the wires are in good condition. Then I will be pursuing the issues you are... 
I want to get it fixed b/c my other cars have always idled prefectly. My Cabrio has 106K miles and my Honda has 97K miles and idles perfectly so I know it isn't mileage... 
Prob do a leak down test soon too. 
Would the EVAP problem throw a code? MY CEL is always off except during startup...
Chris


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

Well I didn't fix my problem yet, but I did get a flat tire driving through a rinky dink half assed construction site next to my work place.
They pull out the "SLOW" sign and the line starts moving, while the construction workers are diving in front of you kicking large rocks out of the way, and doing last moment shovel work before you drive over things that will blow your tire.
Did I mention they were 6 feet off when tearing up the road and had to fill it all back in and start again? The wait is like 15 minutes every day. 
To work. To lunch. From lunch. To home. Every. Single. Day.
My tires are not cheap either. High performance falken.
One more problem on my pallat.
*$%^!!!!!!!!!!!!!!!!!!


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## tiohero (Sep 28, 2004)

*Re: (Busbodger)*

Busbodger,
I will definately replace the MAF and the EVAP one at a time, I am also curious as to what part exactly is causing my rough idle. You think your car has few miles on it... my Jetta has only 75K miles on it and it's idle is way out of whack. It stalls several times a day now. It should be another week till I get my parts in the mail. Also, EVAP problems DO throw CEL codes, that is why I keep getting code P0440. I didn't get the cade P0440 code this last time, which leads me to think that the ECM is not very sensitive to trouble with the EVAP system. Some models of VW's have a Leak Detection Pump for the EVAP system, if your's has it then it will be even more likely that your car will throw a CEL (if there is a leak in your system). I also did the plugs and wires, and it didn't make any difference. However I did not do the cap or rotor, I think I will order those two parts today and see if that makes a difference when I put them in. Here is some info on the EVAP system:


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

What is strange about my car is that it has never died on me once. It just starts a bit harder than it should, and the idle dips very low, usually after driving it hard then letting it sit and idle, it happens like clockwork.
When I start it up in the morning, the exhaust smells fine, like normal exploding gas smell... But after driving it easy around town and stopping, it smells very strange, and not sulphury smelling.
It smells like sulphur when I'm driving it hard, or higher in the RPM's.
Seems to me like something gets hot and messes up or shortsout, because when I stop and let the car sit turned off for a while then turn it back on it seems to run alot better.
It normally runs like crap, but I can get it to run well if I let it sit then turn it back on. How long I let it sit depends on the weather. If it is a nice warm day (70 or above) I can let it sit for 3-4 hours, turn it back on and it will run good for a while.
But if it is raining or cold, the "good start" goes away after like an hour...

WEIRD
I have new plugs, cap, rotor, plug wires...
It never throws a Check engine light.
The only thing it stores is DTC error code 16486, Sporadic low voltage to mass air flow sensor.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

I was speaking to another vw enthusiast in my town, and he said when you smell sulphur, that means the car is running lean, and the cat converter is getting hot which is why it smells like sulphur...
I smell 3 different disctinctive smells coming from my exhaust.
One smells like normal exhaust fumes, which happens when I start the car in the morning, then goes away after the car warms up and usually doesn't smell like this again unless I let the car sit for a long time and the engine gets cold again.
One smells like sulphur, normally happens when I'm running the car hard, or putting any stress on the engine.
The last smell I cannot explain, it usually smells like this when I let the car sit and idle for a while after the engine is warm.
Can someone please tell me if they know what I'm talking about when I say mystery odor, and what possibly is causing it? It just doesn't smell right...
And also tell me WHAT makes the sulphur smell, RICH or LEAN fuel/air mixture???


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## Sam Ontario (Aug 12, 2004)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_The only thing it stores is DTC error code 16486, Sporadic low voltage to mass air flow sensor.

You should concentrate your effort here. 
Correct me if I am wrong, the MAF is supplied with a constant voltage (I guess its 12V) to heat up the sensor and the air flow cools down the heated wire to get the air flow. The air flow signal is fed to the ecm and ecm send out signal to control the fuel injector timing.
Check any broken wire or intermittent wire shortcircuiting from the MAF and trace all the way to the ecm, especially the voltage supply to the MAF.


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## bearing01 (May 27, 2004)

*Re: (Sam Ontario)*

You should be able to tap the signal wire on the MAF and observe it with your volt meter. Measure with the car idling and also note its value as the car's RPM (Air consumption) is increased. It should monotonically rise and fall with rpm.


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## thatvan (Sep 3, 2003)

Can I ask you guys a question? What colour are your spark plugs?
This is usually a very good indication of what is happeniing in your engine. 
Speed--- you seem to have more than one issue-but you did state that your inital plug colour was yellow. Is it the same now? Yellow plugs indicate that you are experancing "high speed glazing" which is caused by rapid tempature increases in the combustion chamber. 
If the above is true I think the best place to look is indeed the EGR system. Sounds as though the EGR valve is stuck partialy open. 
Bythe way Egr valves usually can be removed and cleaned.


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## tiohero (Sep 28, 2004)

*Re: (thatvan)*

Thanks for the info thatvan! http://****************.com/smile/emthup.gif


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## Busbodger (Jul 28, 2004)

*Re: (tiohero)*

Does this car have stock spark plug wires, stock cap and rotor? 
Chris


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

I replaced the yellow plugs about 1 1/2 months ago. I checked my new plugs (which have 1 1/2 mths on them) and they are COMPLETELY White. Not a hint of brown or yellow on or near the porcelain. Running extremely lean?
Again, I don't know how to use the ohm meter thing I have, just a little time after work to figure the problem out. If anyone could write a walkthrough I would print it out and check the voltage/current situation. http://****************.com/smile/emthup.gif


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

ttt


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## thatvan (Sep 3, 2003)

how to use a multimeter---there is a write up on this site. not the best but a starting piont. do a google search on how to use a multimeter.
http://www.bcae1.com/


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## Sam Ontario (Aug 12, 2004)

*Re: (thatvan)*

Speedy,
You may like to fix the exhaust pipes, mufflers after your electricals are checked. Cracks on the exhaust pipes or holes the cat back system will affect the ecm input signals and run your car crappy.
Good luck.


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## tiohero (Sep 28, 2004)

Hey everyone. So I promised you guys that I would let you know if the new MAF and EVAP purge valve I was getting would fix my rough idle. It turns out that my parts were overnighted to me... but lost in the mail. Just my luck, eh? Anyways, I doubt that these parts will ever make it to my house, so I am gonna have to look elsewhere for them. Anyways, I disconnected the broken EVAP purge valve in my jetta and just blocked off the end of the hose that connected to it (the one going from the throttle intake, into the purge valve). After doing that, my car started to run A LOT better. I am thinking that when the EVAP purge valve died, it was stuck open, and it started letting a lot of air into the throttle intake, just like a bad vacuum leak. Anyways, my car is STILL running rough though, looks like I solved half of the problem, but not the whole prob. I will get my hands on the parts that I need for my car, eventually, and hopefully that will steady the rough idle. 


_Modified by tiohero at 7:46 PM 11-12-2004_


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

What my latest guess at this problem is this...
My clutch seems like it engages/disengages diferently at random. Sometimes it releases lower on the clutch pedal, and sometimes higher, like the clutch wont disengage smoothly. It's not a huge deal, and probably only noticeable to me BUT, my theory is:
The motor/transmission mounts have worn out/broken, and the engine/transmission is moving alot, and gets moved different upon take off. This has over time shifted that downpipe weld so many times that it has cracked, and is pulling/pushing out air that and throwing off the o2 sensor's metering.
This is perhaps why my car bucks and runs lean/rich...
My problem is I don't have a car lift to use to check those mounts. Also for decent KCD (SP?) or Turn2's, it's a couple hundred for all replaced. Anyway what do you all think of my theory?
Is it


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## Busbodger (Jul 28, 2004)

*Re: (SpeedRacer20)*

Hey, the clutch cable maybe one of the auto adjust vareities. Replace with a standard manual adjust cable. 
Chris


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

Already replaced the hydraulic clutch cable with a manual adjust cable. Problem was there before and after this mod.


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## thatvan (Sep 3, 2003)

Lets start like this----the sulfur smell comes from the cat overheating. The cat will over heat due to a lean a condition. 
I don't think it is your Evap system as you plugs indicate a normal to slightly lean condition. Though, your plug coloring is not troubling to me. 
So when you got the car it had a bad cat? Cats go bad due mainly to overheating.
You car bucks when you try to accelerate when the RPM's are low (1800-2800)? If you back off the gas or down shift to raise the RPM's the bucking stops? 
You changed all the vacuum lines? What about the ones that go to the Air Control Valve? 
Your car does NOT have an EGR valve, correct?
When you got the car the plugs it had in it had a yellow color on the porcelain? 
Now the plugs are white?
When the car starts to buck do you keep goosing it or do you instantly back off? 
Does your car back fire during deceleration? IE cruising steady then letting off the gas completely without touching it again?
If you can answer these for me ------I think I know what is the problem.
Hint page 26-10 in the Bentley manual.



_Modified by thatvan at 10:44 AM 11-15-2004_


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## SpeedRacer20 (Jan 7, 2004)

*Re: (thatvan)*

I appreciate the reply thatvan.
You think it might be the Air Injection System?
Isn't the AIR system only active when the vehicle is first started up?
Yes when I bought the car a year ago the cat was completely screwed up. Rattled when shaken, and stunk terribly. Replaced it about 6 months ago.
It bucks "more" in lower rpm's 1500-3000 and is less noticable in the higher ranges. The bucking does not happen unless I am going from no throttle to some throttle, or trying to maintain a speed.
For instance, I'm in third gear coming up to a red light, I shift down smoothly, let off the clutch and back fire backfire usually 1 big buck then nothing else once my foot is off the clutch.
Sometimes it's a lot worse than other times... trying to maintain an even 20mph... 30mph... 50mph, it doesn't matter, if it's in a low rpm and I'm trying to go the speed limit, if I let off the gas to slow down then gas it again I'm in for a chug.
Down shifting is a PAIN unless it's running right (about 10% of the time it shifts down without bucking)
What is funny is, the car can be doing this horribly... I can let it sit for 15 minutes, then it will run great for a while, then start doing it again.
it will REALLY backfire if I down shift or let of the gas coming down a hill.
By Air Control Valve, do you mean the Shut-Off Valve for the AIR system shown in Figure 15 on page 26-10?
No, my car does not have an EGR valve.
I don't remember what my plugs looked like when I first changed them. The second time I changed them though (2 months ago) they were dark yellow/brown on the porcelain area.
I checked those about 1 month ago, and those are the ones that are completely white.
The car doesn't buck when I'm accelerating hard, the only thing that happens when I'm gunning it (if the car is running bad) is I get an unhealthy tink tink tink from the engine, like it's misfiring. But when the problem isn't there (like I said, when I start the car after letting it sit) I can go up to 4,500rpm and the engine sounds strong and very smooth, like it's brand new. No tinking, or misfiring...
When the car bucks while I'm coming to a stop I throw in the clutch real fast, and this usually keeps it from happening. I know the car well enough to prevent the buck from happening most of the time.
I also know well enough by now to not drive the car in first gear UNLESS I'm accelerating in to an upshift in to second gear, if I accelerate in first gear then just let off at around 1500rpm the car surges terribly.
YES the car backfires during deceleration. If I cruise steady then let off I get POW POW POW... pop pop pop... so annoying.
THANK YOU for the help man, I have to fix this.



_Modified by SpeedRacer20 at 3:04 PM 11-15-2004_


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## Busbodger (Jul 28, 2004)

*Re: (SpeedRacer20)*

I thought cats overheated when the car ran rich??? Back when I lived in Europe, the Germans were having problems with the autobahn cars that were melting their cats. I was told it was because the cars were running high rpms, and running rich (engine controls ran the engine a bit rich at high rpms...). 
This car sounds like you may have a bad spark plug wire...


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

I had this problem with the plug wires that came with the car when I bought it.
I purchased Blue Ignitor spark plug wires through techtonicstuning about 6 months ago, installed them, and have the exact same problem...
I don't see how the wires could be the problem unless I ruined the wires while I was installing them. I don't think I manhandle them..


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## thatvan (Sep 3, 2003)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_
You think it might be the Air Injection System?
Isn't the AIR system only active when the vehicle is first started up?...

YES!
NO!

_Quote, originally posted by *SpeedRacer20* »_
What is funny is, the car can be doing this horribly... I can let it sit for 15 minutes, then it will run great for a while, then start doing it again.
The car doesn't buck when I'm accelerating hard, the only thing that happens when I'm gunning it (if the car is running bad) is I get an unhealthy tink tink tink from the engine, like it's misfiring. But when the problem isn't there (like I said, when I start the car after letting it sit) I can go up to 4,500rpm and the engine sounds strong and very smooth, like it's brand new. No tinking, or misfiring...

How long will the car run good after you let it sit and restart?

_Quote, originally posted by *SpeedRacer20* »_By Air Control Valve, do you mean the Shut-Off Valve for the AIR system shown in Figure 15 on page 26-10?...

Yes!

This is beyond the Retard Bently manual. I had to dig up some old theroy books from back in school days. I'll answer more fully later at work.

BTW no part of my brain is telling me this is an ignition issue.








If you are bored tonight check into the testing procedures on page 26-10 and look over your car. 
_Modified by thatvan at 10:55 PM 11-15-2004_


_Modified by thatvan at 11:00 PM 11-15-2004_


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Thanks for all the info thatvan! We are all so desperate for solutions and its awesome to have someone giving good advice. Just to let you guys know, I FINALLY recieved a new MAF and EVAP purge valve in the mail today, and I will hopefully replace those parts tonight, and I will let you know if it makes any difference.


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## tiohero (Sep 28, 2004)

*ROUGH IDLE FIXED*

Last night I put the new parts on my car (MAF and EVAP purge valve) and PROBLEM FIXED! The idle is just about perfect! I first put on the MAF and started it up and surprisingly enough, that's what did it! Next I put on the new EVAP purge valve and it instantly started ticking again and doing its job. I am surprised that a bad MAF and EVAP purge valve can affect the idle so drastically. 
I will try to describe what has been going on so far:
When the EVAP valve went bad, every time that I gave it some gas, and then pushed in the clutch (putting it in neutral) the RPM's would bounce between 2K and 3K about four or five times (while the ECU tried to figure out what the hell was going on), and then the RPM's would suddenly dip to about 400 RPM's and then steady out at an extremely rough idle, sometimes it would even stall out. What I did to temporarily fix this was to remove the EVAP valve (the little pump connected to the air box) and I blocked up both ends of the hose that was connected to it with peices of rubber (without the peices of rubber there was a massive vacuum leak going directly to the throttle intake). My theory on EVAP valve, is that when it goes bad, it fails OPEN, therefore, it lets a small but constant amount of air to go directly to the throttle intake. This small amount of air confuses your ECU and causes the RPM's to bounce up and down untill it finally figures out how to steady the idle at a very rough 600 or 700 RPM's. Once I replaced the EVAP valve, it smoothed out my idle a little bit. You can tell the EVAP purge valve is working because it makes a clicking sound that actually sounds louder inside the car (as crazy as that is). Next comes the MAF...
When the MAF went bad, it was not noticeable compared to what was going on with my EVAP valve. Once I took off the EVAP valve and plugged up the hoses, I was then able to isolate the rough idle to the MAF. When I pushed in the clutch and tapped the gas, the RPM's would rise a little and then come back down slowly till it got down to about 600RPM's for a sec and then it would hold steady at about 800RPM's while running a little rough and shaky. I tried taking off the MAF and cleaning the electrodes CAREFULLY with alcohol and a cotton swab... this made no difference. I eventually got a used MAF (in working condition), I put it in and it idle'd rough for about 20 seconds while the ECU adjusted, then it ran PERFECTLY! 
Just for your reference, here are all the OBDII codes that I pulled from the car in the past to help me solve this problem, if you guys have similar codes, then I would suggest following my path to a smooth idle:
On Oct. 8th, I had the engine codes checked at Autozone (thank god they do it for free!), and these are the codes that came out:
P0440 EVAP Emission Control System MAlfunction (pretty common and standard code I am told, but I assume it was related to my bad EVAP purge valve)
P0300 Random/Multiple Cylinder Misfire detected (this happened because I ran out of fuel while driving home on Sept. 29th and the check engine light started flashing)
P0304 Cylinder 4 Misfire detected (see above)
P0125 Insufficient Coolant Temp for Closed Loop Fuel Control (this was because of a bad coolant temp sensor, which I replaced)
P0133 O2 Sensor Circ, Bank 1-Sensor 1 Slow Response. (my O2 sensor is starting to go bad, but it was not related to my rough idle)
After taking a look at these codes, I thought that maybe the coolant temp sensor has gone bad and so I replaced both of the coolant sensors on my car (yes there are two of them because I have AC). I replaced the one for the AC (the one with 2 prongs) with a brand new sensor, and I replaced the main coolant temp sensor (the one with 4 prongs) also with a new one. After this, the car started to run a little bit better, however, the irradic idle was still there and somtimes the car would come VERY close to stalling out. The CEL came on again and I had the engine codes pulled again on Oct. 17th, here they are:
P0440 EVAP Emission Control System Malfunction (same as B4)
P0125 Insufficient Coolant Temp for Closed Loop Fuel Control (same as B4)
P0102 Mass or Volume Air Flow Circ Low Input (only new code I got due to the bad MAF)
The third time I pulled the codes on October 21st, this is what I got:
P0102 Mass or Volume Air Flow Circ Low Input (my MAF was still bad, time to be replaced)
November 15th... my car is now fixed and running smooth!
I hope that this post helps you guys out!















































































_Modified by tiohero at 9:08 PM 11-15-2004_


_Modified by tiohero at 9:11 PM 11-15-2004_


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## thatvan (Sep 3, 2003)

*Re: (SpeedRacer20)*

tiohero- that’s great! I’m glad you were able to fix your ride. My Jetta had only 55000 miles when the idle got all screwed up. Lucky for me it only required the TB and MAF to be cleaned. Don’t know if you remember the old cartoon Heathcliff---but there was a character on it called Mongo who while jumping on a trampoline would say “bouncy, bouncy, bouncy” . That was my idle (sorry long night).
Speedy- I have a few simple tests for you to try. Easy and wont take very long. If we think this thing out we should not have to spend any more useless $$$$!
With the car off, pull the outlet hose off the Air Pump as well as the vacuum line to the Shut Off Valve (SOV). Remove the vacuum line at the Secondary Air Injection Valve (SAIV) side not at the Shut Off Valve side. You’re gonna want to blow into the hose from the pump to the SOV, so if you’re “sensitive” you might want to clean it off first. 
Blow! You should not be able to blow any air through it. 
Try sucking. You should not be able to suck any air either. 
Take the vacuum line and suck. You should hear the valve open. Place the tip of your tongue on the end of the vacuum hose to hold the vacuum in it. It should hold. BTW non-braid covered vacuum hose works better for this. 
Now the tricky part. Lick your finger—suck the vacuum hose until the valve is open---Place wet finger over the very, very little vent hole on the top of the SOV. This should hold the SOV open. Now blow through the Hose running from the pump to the SOV. You should be able to blow now. Should only have a very slight restriction. (Another way is to suck the vacuum hose then kinda get your finger over the end with out loosing any vacuum)
While still holding the SOV open, now suck. You should not be able to suck any air.
Take the vacuum hose and put the end back on the SAIV and remove the other side from the SOV. 
Blow through the vacuum hose. You should be able to. If you smoke take a puff as you can see what is going on better. 
Replace vacuum hose. 
Remove vacuum hose from the other port on the SAIV. Remove it from the other side, not the SIVC as you’re going to suck on this one as well.
Suck! You should not be able to suck any air. Do the tongue thing again as you should be able to maintain a vacuum. 
If all these passed then we need to move on to the running tests as listed in the Bentley—26-10. If not something is wrong.
BTW the relay for my Air Pump is not as listed in the Bentley but on the strut tower. It’s the one with 111 on the top. What the Bentley lists as Air Solenoid is the SAIV. 
If you have access to a lift or jack and jack stands get under the car and make sure the stainless tube running from the SOV to the manifold is in place and the fitting are tight. Also look for holes. Check for holes on the small manifold that the tube attaches to. The small manifold attaches to the exhaust manifold. Check all bolts tight. 
Let me know!
http://****************.com/smile/emthdown.gif http://****************.com/smile/emthup.gif


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## SpeedRacer20 (Jan 7, 2004)

*Re: (thatvan)*

Great information guys, especially thatvan.
I live in a smaller town, where the mechanics really try to rip off the uneducated masses. It costs $67 each time I want the VAG hooked up to my car, and I'm broke off my ass.
I will definetly be trying those tests out ASAP thatvan, and I will get back on here with my results.
Some notes about my car...

1. I have replaced my MAF 2 times, it has never changed my car for good or worse either times.
2. THE ONLY CODE I'VE PULLED IS P0102 Sporadic Low Voltage To Mass Air Flow Sensor.
3. Blows significant amounts of white smoke from the exhaust.
Keep it up guys http://****************.com/smile/emthup.gif


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## thatvan (Sep 3, 2003)

*Re: (SpeedRacer20)*

whoh--------white smoke or water vapor? make sure! 
How long does it last? Just at start up, or all the time? Cold start as well as hot? During deceleration or acceleration? Truly white, or more gray? Any slight blue colour? Is the smoke dense or light?

How is your compression? High---Low? Equal on all cylnders?
Are you having to add coolent and/or oil on a frequent basis?

Any code reader will work if you just want to read codes. Don't you have an Autozone/Advance/Kragen/Pepboys in your town? They usually will read codes for free.
Still think this is mechanical.
_Modified by thatvan at 10:18 PM 11-17-2004_

_Modified by thatvan at 10:21 PM 11-17-2004_


_Modified by thatvan at 11:37 PM 11-17-2004_


----------



## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_
3. Blows significant amounts of white smoke from the exhaust.
Keep it up guys http://****************.com/smile/emthup.gif 

Not good! I think that Thatvan is thinking what I am thinking! My brother bought an old 80's Nissan, and it was blowing a lot of white smoke for a couple of weeks after he got it. One day he was driving up a big hill and the car suddenly stalled on him and would not start back up again. He got a tow and went to work on it. He discovered water in the cylinders. In fact, when he opened up the head he found puddles of coolant in cylinders 3 and 4. On top of that, he was not getting any compression across all four cylinders. He still has it sitting back at home with the engine taken apart. He is having trouble determining if it is a cracked head or a blown head gasket (I am hoping the latter). I suggest you do a compression test of your engine (unless you have already done so).


----------



## Busbodger (Jul 28, 2004)

*Re: (tiohero)*

Leakdown test would be good too. Me think you have a blown head gasket. Is your oil dark or does it look like a cappucino?
Chris


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## thatvan (Sep 3, 2003)

*Re: (tiohero)*

tiohero--- Car still running good?


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## tiohero (Sep 28, 2004)

*Re: (thatvan)*


_Quote, originally posted by *thatvan* »_tiohero--- Car still running good?









It is running incredibly well! It has noticeably more pickup and runs just about perfect. The only problem with the idle is that, while I'm driving around and I push in the clutch, the idle likes to kinda linger about 300rpm's higher than it should for a while, then I give it a few seconds and it drops perfectly to where it should. I think I could solve this by replacing the O2 sensor because I believe it is starting to become flakey. As long as the car doesn't feel like it is stumbling or about to stall, then I am a happy camper. Like I say, I am just surprised that a new MAF could make such a huge difference.


----------



## thatvan (Sep 3, 2003)

*Re: (tiohero)*

tio- did you clean out your TB really good? eesp around the butterfly? also it would be a good idea to clean the whole intake pipe to the TB as the older 2.0's didnt have a baffel plate in the head and you can get alot of oil deposits in it from the PVC system. 
Its great when your car fels new again!


----------



## tiohero (Sep 28, 2004)

*Re: (thatvan)*


_Quote, originally posted by *thatvan* »_tio- did you clean out your TB really good? eesp around the butterfly? also it would be a good idea to clean the whole intake pipe to the TB as the older 2.0's didnt have a baffel plate in the head and you can get alot of oil deposits in it from the PVC system. 
Its great when your car fels new again!

thatvan, 
Thanks for the advice. Last week I actually removed the throttle intake and cleaned it out with engine degreaser untill it actually looked like it were brand new. I especially cleaned around the butterfly and the intake pipe. I did notice when I put on the new MAF, however, that a lot of oil was sitting in the intake pipe. At the same time that I cleaned out the throttle intake, I also reconnected the PCV system (it was cracked off at the valve cover and I fixed it with a new rubber grommet). Because of the fact that I reconnected the PCV valve, there is now lots of oil in the intake pipe. Is this harmful? Also, what is a baffel plate? It is interresting... when I took off the PCV valve, I sprayed it THOUROGHLY with engine degreaser as well, I then let it sit for a couple days untill the degreaser dried up. I then took the valve and started banging it against the floor and this dried up crap just started falling out, and out, and out... I am assuming that dried stuff was oil that dried up and become hard. I would have just bought a new valve, but they cost $65 at the stealership. Anyways, thanks for the info!


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## thatvan (Sep 3, 2003)

*Re: (tiohero)*

I sometimes love VW and their screwball designs! Been down the road you're going. Inside the "PVC" valve is a diaphram that kinda acts as a check valve as well as a oil stop. It is real delicate and can be ruined easly. I used carb/intake cleaner on mine and ruined it. If it is gone there is nothing to stop the oil that is somewhat vaprised (mist) to enter the intake pipe. To be politically un-correct----what a gay design! F'n Germans------we don't need an oil filter as our air cleaners are so good!------old aircooled motors----
Later 2.0's have a baffle plate installed in the valve cover (originally installed on TDI's) to stop some of this oil vapor. I don't know what exact year but it is my understanding that they were installed on later OBD11 models. 
Germanautoparts has the PVC thing for like 45 I think. Thats where I got mine from. http://****************.com/smile/emthup.gif


----------



## tiohero (Sep 28, 2004)

*Re: (thatvan)*

Thanks again for the advice! The oil seems to be really getting spit into the air intake hose. I had better get a new PVC valve soon, I just find it so strange, the way that PVC valve is designed; it's totally unlike any other car. 

_Quote, originally posted by *thatvan* »_
we don't need an oil filter as our air cleaners are so good!------old aircooled motors----


I didn't know this! Very interresting! What cars was this on? I'll bet some people prob had to install their own system of oil filter on these?


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## thatvan (Sep 3, 2003)

*Re: (tiohero)*


_Quote, originally posted by *tiohero* »_I didn't know this! Very interresting! What cars was this on? I'll bet some people prob had to install their own system of oil filter on these? 

All aircooled--Bug/Bus/Fastback/KG/SQback/Thing/Notch. Some do! Though the engine was originaly designed very sloppy(tolerances are very loose) anyway so the longivety is low. But cheap and easy to rebuild. I once rebuilt one on some ladys front yard in Lincoln Ne after I poped a cylnder.
The whole point of the design was so some poor german farmer could rebuild his engine on the farm without tne need for special tools. And because the car (bug) is so popular in third world countries VW felt is was best to leave it easy to work on. BUT STILL they could have put a oil filter on 'em.


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## Busbodger (Jul 28, 2004)

*Re: (tiohero)*

Yeah all the old aircooled VW engines (Beetle, bus, Ghias, Things) came without oil filters. The '72 and up Busses had the Type IV engine which did come with an oil filter. 
LOTS of folks have added an oil filter and FWIW the last of the Mexico air cooled Beetles had oil filters. 
Chris


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Busbodger)*

Just got a new ISP, and will be doing the test on my car. I will let you guys know exactly what was wrong with my car when I get it fixed, even if it's not going to happen soon.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Any new developments Speedy?


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

I have recently talked to a few other VW nutheads like me, and they agree with my Downpipe leak/buzz theory.
See my other new post called
"Replacing downpipe on 96 Jetta - DIY or walkthroughs anyone?"
Thanks for replying to my newest post, I will definetly post all over the place on here if this solves my problem.
Right now I'm waiting on funds to put in a new downpipe.
I'll keep you updated.
By the way, post your thoughts on the downpipe leak/02 sensor idea of mine. http://****************.com/smile/emthup.gif


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

OK fellas latest news.
Bought a slightly used downpipe from BW parts. Pulled out my old downpipe which was welded and rickety looking.
Installed the new downpipe which came with an 02 sensor, which was good cuz I couldn't get the old one out (even tried heating it up).
Anyway, the rattle is GONE so any of you with a "heatshield rattle", I'm betting it's the sleeve that surrounds the downpipe (it's all one piece).
On a more sad note, the bucking is still there, the idle drop is still there. Check engine light is ON (explained down below). Still loses power. Engine still sounds weak and knocks when I'm gassing it hard.
I reset the computer after installation as well. (Negative battery cable off for 30min, back on for 5, let car idle for 5, test drove car.
Anyway It's been 1 week since I installed the new downpipe and new gasquets top and bottom. The car has a tad more power and sounds better, but the main problem still exists.
I have been driving it ALOT lately, nearly 1000miles in 1 week (for work) and I was very disappointed the car still acts up. Gas mileage is still lower than it should be. Exhaust still stinks like sulfer, and the other odd smell I couldn't describe. Only on start up does the car sometimes smell like regular gas like it should.
This all makes me start at square one that the DTC code was telling me.
"Intermittent low voltage to mass air flow sensor. Sporadic DTC"
Now I think to myself it could either be
A. Computer wiring harness.
B. Computer
C. Relay
D. Battery
E. Alternator
As I've stated in another thread I have going, my stereo will lose power as well. Someone was telling me something about a "K" wire that the stock harness plugs in to the stock stereo or something, and if you don't cap it off it will short out your aftermarket stereo and mess with your electrical OR SOMETHING like that. I'm still researching that whole deal. Anyway that is another lead I may have.
As I stated before, the car will idle up and down up and down when I'm at a stop light or whatever, then the idle will go way up (1200rpm) then stabilize back at 950rpm or so.
*When the car does the idle drop, I can hear the air pump (the little black pump that connects to the air line that comes out of the throttle body) go from it's normal knock knock knock sound it makes when it turns itself on at idle, to a super fast knocknockknock sound when the idle dips.*
Let me phrase that a different way.
Everytime the cars idle dips up and down, I can hear the air pump start freaking out and pumping way to fast. I assume it's pulling way too much air out of the throttle body and that messes with the mixture of air/fuel and makes the idle dip up and down.
OK, so I deducted that when that air pump spazzes, the idle dips up and down. So to test my theory, I pulled the electrical plug off of the air pump to turn it off, but I left it connected to the air hose.
Idle dip GONE. With the air pump unplugged from the system (but still connected to the air hose) the idle problem has been removed.
OK problem, solved, I just need to figure out why the pump has a problem.
Could it be the pump itself is bad, or this is a byproduct of my car sending low voltage to miscellaneous components on my car?
I don't want to throw a new air pump on it yet, I'll explain why.
OK, so when I unplugged the air pump, I knew this would throw a check engine light. I also knew, I could just plug the pump back in, reset my computer and it would get rid of the CEL light, and go back to normal. I knew this because I did the exact same procedure before to get the CEL off after unplugging the air pump.
Well this time it didn't work that way. I unplugged the pump. I got a CEL light. I unplugged the negative battery cable for 30 min and did the whole reset procedure. I started up the car.
CEL LIGHT STILL ON.
I did the procedure again. I started up the car. I drove it for a few days.
CEL LIGHT STILL ON.
Also bear in mind for the last month I've been having a very strange unhealthy BUZZ coming from my engine bay. I believe I explained this on this thread a while back.
The buzz only lasts for a few seconds and usually only does it upon cold startup. It lasts so briefly, and intermittently, I can't flip open the hood and jump inside the engine bay to locate the buzz.
Well now that buzz lasts alot longer now, and will rear it's ugly head just any old time now. It will change in pitch and how loud it is as well.
It doesn't just do it on start up now.
So where is this buzz coming from? Well I believe it's coming from the alternator. I stuck my head as close as I dared to the alternator, and I believe that's what is making the noise. I replaced all my belts and did my timing a while back, so it COULD be a belt, but that's not the kind of noise it's making. I don't think...
So if it is the Alternator, that could throw a CEL light.
By the way I haven't had a CEL light on for a very long time, just the DTC code Low voltage to MAF sensor.
OK guys that is the update and where I stand now.
Intermittent buzzing coming from engine bay.
CEL Light is on.
Intermittent loss of power to stereo. (stereo sounds weak)
Intermittent idle dip. (because I reconnected the plug to the air pump for now)
Intermittent air pump spazms. (note that the air pump runs correctly 75% of the time, and sometimes it runs super fast and then the idle dips up and down. After the pump goes back to normal, the idle goes back to normal)
Intermittent sulpher smell from exhaust.
Intermittent engine loss of power ( most likely caused from an electrical component losing voltage/voltage drops altering the fuel/air mixture.
Car always starts first try (though sometimes it starts up instantly, sometimes it takes a second longer if it's running like s%*t.)
Car intermittently bucks when maintaining a constant speed, or upon deacceleration and then reacceleration.
There you have it guys. I'm scheduled today at 12:00noon to have the car put on a standard Diagnosis machine (he doesn't have a VAG and that costs 70$ each time I do it elsewhere). The mechanic I'm taking it to was the first mechanic to tell me it was getting low voltage to MAF, and then I took it to VW dealerships/specialists with VAGs and they confirmed the low voltage DTC.
I am hot on the trail with this god damned maddening electrical gremlin, and I will keep you all posted after we figure out why my CEL light is on.
I love my f*$!ing Volkswagen more than ever!


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## R3 (Jan 20, 2002)

*Re: (SpeedRacer20)*

Do MK3's have knock sensors? I know that older cars did, but I am not sure about the MK3's. My fiances car does the exact same problem that has been mentioned in this thread and the other 14 page thread. I even went through that whole thing!!
Her car doesnt have an idle issue really, just the bogging down from 1.5k rpms - 2.5k rpms
We have replaced the MAF, plugs, wires, cap, dist, rotor. I also cleaned out the TB. I am leaning towards the cat/o2's or maybe the knock sensor since it is only at lower rpms.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (R3)*

Well I had my car put on the diagnostic machine, and it pulled a code referring to the Ventilation system. I unplugged the wire going to the air pump and plugged it back in and the code went away as well as the check engine code... I guess there is a posibility I didn't plug it in all the way although that seems odd and I usually am very good about that kind of thing.
Ok let's dismiss the CEL light now because it is off.
Also, I had him check out the Alternator and it checked out at a solid 14.0 - 14.5 Volts, which is fine.
So as me and the mechanic (whos name is Laszlo) stood there and debated why my car runs like ****. If it's one problem. If it's several problems.
As we stood there talking and my car was misfiring every 2-5 seconds or so, I noticed the water coming out of my tailpipe, which it usually does. But it was really dripping. It usually does this, at least at idle which is when I notice it. Is this normal? I mean it is a steady drip drip drip and after a few minutes there is a small puddle beneath the exhaust tip...
Anyway, we were talking about the fuel pump, so I decided to listen with a stethoscope to see if the fuel pump was cutting out or hesitating.
Put the stethoscope on the fuel tank... and the buzzing of the fuel pump would cut in and out exactly the same time the exhaust would sputter and the car would misfire......

Hmmmm....
Now again I question, is the fuel pump the problem, or is something else shorting/losing voltage and causing it to cut out...

I am so fully frustrated with this problem, I told him to KEEP the car and go over the entire vehicle Top to Bottom and take note of ANYTHING and EVERYTHING that is questionable, or definetly needs replaced. As he finds parts that are bad/going bad, he will let me know and I will see if I want to buy it new/rebuilt or from techtonics tuning so I can get a better price.
This is my last resort, I'm leaving it up to him to search out this problem, but I will continue researching so I can help him out with any info I can find.
The problem will be solved, it's just a matter of time.
*At this point in time, the situation with the car is as follows.
Misfires every 2-5 seconds.
Watery substance constantly drips from exhaust tip.
Alternator checked out fine.
CEL Light OFF
Idle dips up and down the same time the air pump on the EVAP system pumps extremely fast.
Fuel pump cuts in and out the same time the car misfires and sputters.
Apparently the 02 sensor that came with my new downpipe is working properly since the car has not thrown a code for the sensor, and it runs the same as it did with the brand new 02 sensor. (I did not put in my new 02 sensor in to the new downpipe because I could not remove the new 02 sensor from my old downpipe.)*


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## FL 2.0L (Aug 1, 2002)

I have been following your troubles for awhile now. I still think ignition every time you describe the way the car misfires...


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## tiohero (Sep 28, 2004)

*Re: (surferfletch)*


_Quote, originally posted by *surferfletch* »_I have been following your troubles for awhile now. I still think ignition every time you describe the way the car misfires...

I would like to believe it is his ignition too... my car has the EXACT problem as speedracer's and I even changed out my ignition coil and the car still has exactly the same problems as it always had.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Speedracer, 
It's nice to see that you are not afraid to keep searching for the source of the problem. I have been banging my head over this for months now







. I changed out the MAF and the rough idle went away. I also changed out the evap purge valve (little air pump connected to the tube that goes to your throttle intake) and my idle got better as well. But my car GUZZLES gas like there is no tomorrow (17mpg and its a stock 2.0L)! I keep looking at different things under the hood... I changed out the ignition coil and I have tested the O2 sensors thoroughly... yet my car still guzzles gas and stinks like sh**. I want to thank you for documenting everything as well so that those of us with similar problems can get to the bottom of this! Good luck and I will keep you posted if I figure anything out as well.


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## Guidofester (Aug 28, 2003)

*Re: (surferfletch)*

I have a 96 Jetta that I am working on with a similar problem. We have replaced most of the ignition parts in order to eliminate possible problems (Plugs, wires, cap & rotor,) We tried a brand new coil and when that didn't change anything we installed the old one.$$$$$.
One thing that I haven't seen mentioned is the Dizzy. I'd like to replace the dizzy and see how my problem changes. I'm also looking to swap my dizzy into another car in order to make sure that the original dizzy is in good working order.
Has anybody else had a problem with their dizzy?
P.s. any body have a dizzy for sale.?


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## Sam Ontario (Aug 12, 2004)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_OK fellas latest news.
Let me phrase that a different way.
Everytime the cars idle dips up and down, I can hear the air pump start freaking out and pumping way to fast. I assume it's pulling way too much air out of the throttle body and that messes with the mixture of air/fuel and makes the idle dip up and down.


You have leaks. Could be your PCV venting system problem which can also give you the sulfur odour.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_OK fellas latest news.
Let me phrase that a different way.
Everytime the cars idle dips up and down, I can hear the air pump start freaking out and pumping way to fast. I assume it's pulling way too much air out of the throttle body and that messes with the mixture of air/fuel and makes the idle dip up and down.

Keep in mind that the EVAP purge valve pushes fuel vapors that are trapped in the charcoal canister INTO the throttle intake so that these fumes are burned up in the cylinders. It is interresting though... my EVAP purge valve also seems to be going haywire all the time and I wonder if it is connected in some weird way to my gas guzzling problem??? My question is... what is controlling the EVAP purge valve... in other words: what causes it to pump so fast? I think that it may be INDIRECTLY related to our problem. Just throwing in something to think about.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_Hmmmm....
Now again I question, is the fuel pump the problem, or is something else shorting/losing voltage and causing it to cut out...

Speedy, don't be too intimidated by the fuel pump if it has to be replaced... apparently it is very easy to replace on our cars because it is accessible underneath the floor cover in the trunk. Usually you have to remove the entire fuel tank to change it out and that can be a PITA!


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

The PCV hose on my car is new, as well as the PCV elbow. The PCV reservoir was throughly cleaned a while back too. I don't think that would be the problem.
The other day at the shop I put my car on a fuel pressure tester. Long story short I was steady at 32PSI and it would dip way down if I pressed on the accelerator... Thus the bucking problem?
My spark plugs were checked too and they are very very WHITE, they look brand new. This shows the car is running extremely lean... Thus the sulphur stinking problem?
Anyway, I listened to my fuel pump under the mat in the trunk, and it is making a noticeable whining sound.
Everytime the car misfires at idle the fuel pump CUTS OUT...
I have a new fuel pump coming in today and I will be installing it very shortly.
Everyone who is having this problem, lift up the mat in your trunk, and remove the 3 screws that holds in a round plate. This is your access to the fuel pump. Put your ear up to it and see if it cuts out or is making a whining noise. This is a sign of a weak or failing fuel pump.
I hope this is the problem... I will post again after it is installed.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Awesome Speedy! It looks to me like you are hot on the trail! Keep in mind that some people on the Vortex have had to replace their fuel pum relay and it sells for something like $10 on germanautoparts.com ... that is JUST IN CASE the actual fuel pump is not the problem. My brother has a stethescope so I might try to listen carefully to my fuel pump tonight to see what mine sounds like too. I realized something very important today in regards to MY car. For a long time I had a suspicion that the little valve on the bottom of the inside of the airbox was stuck open so that only HOT HOT HOT air from behind the exhaust was going into the engine. I finally tested it out.... before I left Plattsburgh to come home to Ithaca (300 mi. journey) I unplugged the vacuum line that goes to the side of the airbox that pulls the valve open to let hot air into the air box (normally the valve is stuck closed untill you start the car and then the vacuum line starts sucking and pulls the valve open to allow hot air from behind the exhaust manifold to enter the engine for COLD STARTUP ONLY). So basically the car was only going to be able to suck in cold air like it is supposed to with the vacuum line disconnected. I drove the 300 miles home and I got 31mpg for the first time ever!!!







When I got home and opened up the hood the unplugged vacuum line was still sucking air very strong. I opend up the air box and plugged in the vacuum lineback into the side of the box, and sure enough the vacuum pulled the little valve open *when it is not supposed to* because of the fact that the engine is HOT already. If the engine were cold this would make sense, but my temp gauge said it was hot and I had just driven 300mi. So I am going to keep this vacuum line permanently disconnected so that the engine can get cold air and run much more efficiently. I am suggesting that those of us with horrible fuel mileage check this out because it is a simple problem, an easy fix and it will save you a lot of money on fuel so you can buy more





















And celebrate that your car is running better! 


_Modified by tiohero at 7:10 PM 2-4-2005_


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## FL 2.0L (Aug 1, 2002)

*Re: (SpeedRacer20)*

Sounds like too simple a fix, eh? Hope it solves the problem!


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## Minglor (Jul 26, 2004)

*Re: (surferfletch)*

ttt


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_
Anyway, the rattle is GONE so any of you with a "heatshield rattle", I'm betting it's the sleeve that surrounds the downpipe (it's all one piece).


I know this is off topic but you can also put a pipe clamp around the broken part on the heat shield. It literally takes 2 minutes and the broken part is very accessible. http://****************.com/smile/emthup.gif


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

The way the it splits to dual pipe and the way it is shaped would make it difficult to put a pipe clamp on the downpipe. Besides if it's rattling like a mother it could mean there's a hole in it anyway and that's best fixed by just buying a slightly used one for $100.00 at BW Parts.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_The way the it splits to dual pipe and the way it is shaped would make it difficult to put a pipe clamp on the downpipe. Besides if it's rattling like a mother it could mean there's a hole in it anyway and that's best fixed by just buying a slightly used one for $100.00 at BW Parts.

True, but in my case a simple pipe clamp did fix the rattle 100% (that rattle was LOUD and extremely annoying). I think that it all depends on where the heat shield separated from the exhaust pipe. On my Jetta it separated right at the bottom before the cat which is the best spot to wrap a pipe clamp around it. Unfortunately I still have to replace the heat shield that is right above the exhaust and right behind the engine. I tried to replace it once already, but it was such a PITA and I didn't have enough time so I let it go untill I have some more time.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

Hey, I've been busy with work and haven't been on the vortex in a while.
The latest thing I've done to my car is install a brand new fuel pump and fuel filter. Overall the car runs better, but the car will still buck and chug while trying to maintain a speed, let off the accelerator and gas it again.
About the only thing I have not replaced so far is the fuel pump relay, the main ECU (computer), the ECU wiring harness, and the air pump/valve.
When the car is idling it still misfires and just sits there and shudders every 5-10 seconds. The shudders aren't very big, but it still happens.
Just before I put in the new fuel pump I checked my spark plugs and they are still VERY white and clean looking. ....... Car runs lean.....
After driving for a while and stopping at a stop sign or a light or whatever, the engine drops in RPM's and does the up down up down thing while the Air pump goes in to spasm mode.
I wouldn't say putting in a new fuel pump was a total loss, this one is alot less noisy, and the car like I said runs overall better, more power, better mileage etc. But the problem still exists, so if you're all having the same problem as me, leave the fuel pump alone cuz it's probably not bad.
At this point we're looking at 
1. Air pump/solenoid (the thing that probably is making the car idle erratic when car is stopped)
2. Main Computer (This is the ECU. I have put in a new ECU Chip from techtonics tuning a while back, and tried swapping out that for the stock one, but it makes no difference which Chip I have installed, the problem persists)
3. Fuel Pump Relay (If anyone knows off hand what number relay this is, chime in. If no one knows I will find out when I go to replace it and post that info here)
4. ECU Wiring harness. (This is the wiring that feeds off of the ECU and goes to all your electrical parts in the engine bay)
I will keep you guys informed of what is going on. I am still very much determined to fix this problem. I still love my Jetta and wouldn't trade it for anything. I did drive a 2005 Subaru WRX STI a few weeks back, but that still left me unusually content with my 125 HP Volkswagen


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

Ok guys quick update. I took a drive from SouthWestern Oregon (Brookings) down to Santa Rosa California, then up and over to Redding California, then back up to Southwest Or.
The car did the same it always does, runs like a raped ape sometimes, and other times it seems like it has asthma.
Misfires. Loses power slowly. Engine tinking noise. Idle dives up and down when sitting at idle.
One thing I've noticed that I may or may not have mentioned is that the clutch seems to engage/disengage differently depending how the car is driving. This is fairly hard to explain unless you've driven the car. To summarize though, let's just say the car shifts through the gears and launches from first gear differently, but I don't know why it happens or if it is related to the other problems.
Anyway, this problem has been ongoing. I replaced the transmission a year ago as well as putting a new clutch in. When I had this work done and got the car back, I noticed I could hear a tinking sound when the car was in gear and the clutch was pressed in. But if I put the car in neutral, and let off the clutch the car would stop making the tink tink tink noise.
I took it back to the mechanic and he fixed it. I don't know what he did or what the problem was, but it stopped doing it.
But lately (when I got back from my long trip) I was at a stop light, and took off normal and the clutch slipped and the vehicle went in to a full body chug until I completely took my foot off the clutch.
From what I can tell, the clutch seems to slip WAY to easily, considering the tranny has 15k miles on it and the clutch was new as of last year, and I drive the vehicle very smooth...
Now wtf? Could these problems be related with each other?
I have always had to shift smooth and fast with the idle problem or the car would jerk.
Well there is the update. I don't know what is going on here










_Modified by SpeedRacer20 at 4:13 PM 3-25-2005_


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

Well there we have it, the car finally *died* on me. It was doing the up and down up and down idle thing until it didn't come back up.......
Started it back up and the idle does the same thing up and down....
NO CEL LIGHT
As it was doing this up and down idle dip I unplugged both O2 sensors, and the MAF sensor.
NO change in idle behavior, and the CEL light didn't come on either.
sigh..


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## FL 2.0L (Aug 1, 2002)

It's your coil.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

How much of the exhaust have you had repaired? Was it everything from the exhaust manifold DOWN? Or was it everything from the cat, down? Also, do you smell the sulfur smell from inside the cabin while you are driving, or is it only when you are stopped at a light? 


_Modified by tiohero at 11:30 AM 3-27-2005_


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*


_Quote, originally posted by *tiohero* »_How much of the exhaust have you had repaired? Was it everything from the exhaust manifold DOWN? Or was it everything from the cat, down? Also, do you smell the sulfur smell from inside the cabin while you are driving, or is it only when you are stopped at a light? 

_Modified by tiohero at 11:30 AM 3-27-2005_

I've replaced the exhaust manifold, the downpipe, and the catalytic converter. I have not replaced any piping after the cat or the muffler.
I can't smell the sulphur smell when the windows are closed, but on a day when the windows are down it stinks pretty bad.
Tell me what you think of this theory...
The coil has a hairline crack in it which I epoxied a while back which changed nothing, which you guys already know.
Let's just say that the coil is the problem for the sake of argument
The coil is bad, which is sending bad spark or erratic spark to the distributor cap, which in turn is making the car misfire badly.
The computer in turn, sees this constant misfire on some or all cylinders, and immediately puts the car in to limp mode, and stops using the readings from all sensors (o2, mass air flow, coolant sensor etc.) Perhaps this is why I can unplug my sensors and it will not change the car at all, and other times I unplug the sensors, the car stumbles and fumbles then evens back out (which I assume it goes in to limp mode instantly)
When the car goes in to limp mode, the car initiates a predetermined air/fuel ratio to keep the car running. Let's just say this air/fuel ratio is inaccurate to say the least, and makes the car run lean. This constant lean mixture problem is what is making my car run so hot, and is burning up my cat converter,(which happened) burning and cracking my exhaust manifold(which happened) and burnt up the flex weld on my downpipe (which also happened).
I know for a fact that there are pin sized holes in my exhaust piping after the cat converter. Those I don't believe cause any problems, since they are after the cat and o2 sensors. But what if the cat converter running so hot for so long and creating that terrible sulphur smell when running for a while, blew parts of it's honey comb right into the muffler and is clogging it up, creating tons of HOT backpressure killing my o2 sensors and my exhaust system all at once.
At this point, I'm going to order a tested good used Coil from BW parts, and will be getting it in a few days. I may also be ordering another 02 sensor, because I don't want to chance the one I have in there being bad.
THe coil used is $50.00 which is not bad, and the o2 sensor is probably going to be even less. These parts come with a 6 month warranty which is also pretty nice.
Anyway thanks for responding guys, hopefully this problem is almost solved.
Let me know what you think of my theory above.
Also let me know what you think about this theory....
When I start up the car first thing in the morning (cold start) the gas smell from the exhaust pipe smells NORMAL, like a gasoline smell.
But when I take off and drive for a few minutes and stop, the smell is very strange, and nothing like gas. I assume this smell is when the car decides to run lean from being in limp mode (when it's not taking a reading from the sensors)
After I get done driving the car hard, or after pulling a long hill, the smell is like sulphur or rotten eggs. This I assume is from the cat over heating from the lean condition and that is the honey comb inside the cat being ruined.
So In summary, when I FIRST start the car up, the computer doesn't have time to realize the misfires and change the air/fuel ratio, that's why it smells normal for a few minutes. But after that, the smell changes to lean after the computer realizes how bad the misfires are.
What do you guys think of this?


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## FL 2.0L (Aug 1, 2002)

I hope it's the coil...


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## SpeedRacer20 (Jan 7, 2004)

*Re: (surferfletch)*

I have a coil, an Evap regulator valve (the clicker), and a 02 sensor all coming in a few days. Will let you guys know the outcome.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

Well here's how it went.
Unplugged battery for about 1/2 hour.
Installed the coil, evap purge regulator, and the 02 sensor.
Reconnected battery.
Waited 5 minutes.
Turned key on.
Waited 5 minutes.
Started car. 1 minute later the idle was dipping up and down severely. This lasted about 2 minutes when finally the car died.
I didn't touch the gas pedal once during the episode.
Restarted car.
Drove around for 1/2 hour.
Car feels exactly like it did before.
Car still smells lean and stinks like sulphur.
Car has not died again since then nor has the idle dipped up and down severely in that half hour of driving it.
The car did not have a very steady idle though (car still misfired)
I'm going to let the car completely cool down then drive it again two more times before I make a conclusion, but at this point I'm not feeling very lucky.
BTW the old o2 sensor looked kind of white and burnt, not black at all.
someone needs to fix my car for me










_Modified by SpeedRacer20 at 1:43 AM 3-31-2005_


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## FL 2.0L (Aug 1, 2002)

Damn.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

This is crazy! I bought the CarChip from Davis Instruments to try and diagnose my car troubles... but the interface and the software is honestly pretty lousy. I think I am going to sell it on ebay and get a Vag-Com instead. The Vag-Com is extremely powerful and I know for certain that I could learn a lot from it. 
EDIT: I did notice something interresting with the CarChip however... my fuel trim is constantly stuck at -10.94%







Shouldn't it be adjusting up and down depending on engine conditions







. Problem is: my car gets 13mpg city and 29mpg highway. I wonder if Speedracer may have his fuel trim stuck at a certain parameter like I have. Maybe when I get a vag-com I will be able to diagnose a little better.


_Modified by tiohero at 5:59 PM 3-30-2005_


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

Keep us informed


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

Ok well, car still has problems, nothing has been fixed.
My car's exhaust sounds "throaty" to say the least. It has sounded that way since the day I bought it.
It also sounds kind of raspy, especially when I'm gassing it.
I'm not sure why the car sounds louder than stock, but it may be the muffler.
The muffler is all rusty, so I'm trying to decide whether or not that could be a problem. Perhaps the old cat converter's internals blew apart in to the muffler and has clogged it up.
My question is, if I hack that muffler off and the rest of the exhaust from the muffler down, how loud exactly would it be?
And would I suffer any bad side effects like, huge reduction in torque?


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## golf strom (Jan 14, 2002)

*Re: (tiohero)*


_Quote, originally posted by *tiohero* »_
EDIT: I did notice something interresting with the CarChip however... my fuel trim is constantly stuck at -10.94%







Shouldn't it be adjusting up and down depending on engine conditions







. Problem is: my car gets 13mpg city and 29mpg highway. I wonder if Speedracer may have his fuel trim stuck at a certain parameter like I have. Maybe when I get a vag-com I will be able to diagnose a little better.

_Modified by tiohero at 5:59 PM 3-30-2005_

This would likely be a result of "a broken wire from the front O2 sensor I would bet a few people her mention that they have replaced the O2 sensor wut did they use a universal replacement and NOT replace the wire harness from the original sensor. Remember that those wires are routed near some really hot locations and I would put money on it that they became so brittle that the wire broke inside the insulation. Just a thought.


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## tiohero (Sep 28, 2004)

*Re: (golf strom)*


_Quote, originally posted by *golf strom* »_This would likely be a result of "a broken wire from the front O2 sensor I would bet a few people her mention that they have replaced the O2 sensor wut did they use a universal replacement and NOT replace the wire harness from the original sensor. Remember that those wires are routed near some really hot locations and I would put money on it that they became so brittle that the wire broke inside the insulation. Just a thought.

Hmmm... that could be a possibility. Although I monitored the O2 sensors through the ECU and they were giving out normal readings. I am getting a VAG-COM in the mail in a few days, so maybe that will point me in the right direction.


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## golf strom (Jan 14, 2002)

*Re: (tiohero)*

did u look at the readings for the front AND rear sensor. The two sensors work in tandem. If one is sending bad info the other one will try to work outside its parameters. Although the front one is the critical one as it is mainly responsible for the fuel air mixture. \
Oh and don't forget that a internally broken wire MAY work fine while the car is sitting but may fail while the car is in motion. I woud suggest gently pressing on various sections of the wire harness to BOTH sensors. You may find an intermittent connection. Even better drive the car while you monitor the VAG make sure to go over some bumpy roads as well. Also spray electrical contact cleaner on all connectors. 
One little thing i have found that might be lost on most here....There is a ground connection where the distributor cap is secured by metal clips to the distributor body, you will see where the clips fit on the cap itself tiny metal strips on the outside of the cap and the clips from the body contact that part of the cap creating the groud. Spray contact cleaner on these strips of metal and the clips make sure they are clean, use medium steel wool( make sure the battery is disconnected before you do this) clean wool metal residue away before reconnection of battery. Also where the metal clips hinge on the body of distruibutor spray contact cleaner and brush (gently with a tooth brush) the piviot points clean. This is a ground point that can cause acceleration problems if it is dirty. Good luck. 



_Modified by golf strom at 6:15 PM 4-4-2005_


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## SpeedRacer20 (Jan 7, 2004)

*Re: (golf strom)*

Ok fellas between me moving etc etc, I have been offline for a few days.
The result of the VAG diagnostic session was this.
Mechanic could not pull a VAG code or even a DTC code for my car. He did agree it was misfiring constantly.
He ran the car through all of the adaptation procedures.
He noticed (as I had noticed a while back) that the exhaust doesn't sound stock. It does also make a slight whistle noise when accelerating. He thinks that a baffle in my muffler broke loose, and is intermittently blocking air flow through the muffler. This could also have been amplified by the old cat converter breaking apart and clogging it worse.
He told me it is totally possible that the exhaust smells funny, the car runs lean, AND the back pressure was created and ruined my whole exhaust just by the muffler being clogged up.
My exhaust always sounded throaty, back fired, crackled and popped on downshifts. And the exhaust has always been OEM.
He suggested I disconnect my exhaust system from the cat converter back. So that night I pulled off my cat, the piping and the muffler.
Obviously I left on the manifold and downpipe as well as the front o2 sensor.
When I took it off, the muffler was rattling big time. The cat converter however did not look damaged, nor rattled when I shook it. I looked inside of it and the honeycomb was white (probably from running lean so long) but I don't think there was damage.
I also had to disconnect the rear o2 sensor (connected to the cat) so I was expecting a CEL.
Well I drove the car 2 hours (to my new home) and the car sounded like a dragster. Deafening loud. It was hard to hear the engine.
BUT...
I stopped numerous times to smell the exhaust and it actually smelled like gas.
The car as a whole, felt more solid (no shaking, stuttering...no loss of power like it was having.
But as alot of you know, removing the cat, the muffler, and the piping reduces all backpressure, which on our cars, where our torque at low rpm's is where most of our power is. This made the car lose low end power, and on top of that the car was loaded all the way down with my salt water fish/tank/equipment.
Anyway I went ahead and ordered the techtonicstuning cat back exhaust system with the borla muffler. I live where roads are maintained without using salt etc. so I bought the aluminzed version found here http://techtonicstuning.com/vi....431B
I'm a little worried that the cat converter, although it doesn't look bad to me, may in fact be damaged and cause problems with the new exhaust. Hopefully though, it wasn't on the system long enough to have been damaged (about 8-10mths.)
If this problem is fixed from the new exhaust, I will definetly let everyone on the tex that complains about "rattling exhaust" know that it's probably causing more damage than they know.
The OEM muffler and piping bend design is pretty strange looking to me if you ask... seems like it was begging to be replaced.


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Can't wait to hear the results! http://****************.com/smile/emthup.gif


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## R (Oct 28, 2000)

*Re: (SpeedRacer20)*

I think that the cat back will help some of your problems for sure.
First question, do you have a Bentely (or other good)repair manual for your car? If not you need to get one asap. One of the key things that you get from the manual is a description of each system's purpose, and a general breakdown of how it achieves it's goal. Plus how the parts of the system interact with each other. All of which make diagnosis much easier.
Let's go down this list.
Intermittent buzzing coming from engine bay.
That buzzing is coming from the throttle body. If you lift the hood, roll down the driver window and turn the key to the run position (don't start the engine)from outside the car. The buzz should last long enough for you to verify that.
CEL Light is on.
Intermittent loss of power to stereo. (stereo sounds weak)
There is a service bulletin from vw about after market stereos. But I think it has more to do with warning techs of a possible voltage problem that can damage test equipment.
Intermittent idle dip. (because I reconnected the plug to the air pump for now)
Intermittent air pump spazms. (note that the air pump runs correctly 75% of the time, and sometimes it runs super fast and then the idle dips up and down. After the pump goes back to normal, the idle goes back to normal)
There are two different evap emission systems that vw put on 96 2.0L. 
One has a LDP (Leak Detection Pump) with a large canister mounted behind the RF tire. The pump is in front of the RF tire near where the receiver/dryer tank for the a/c is located. If you have that system you will have the small black plastic air filter mounted on the strut tower. The small valve in line to the throttle body is the evap purge regulator valve.
The other system has a charcoal canister under the air box. That is where the other end of the hose from the throttle body goes.
Quickly how it works. One of the three hoses that come from the gas tank is a vent line connected to charcoal canister. The hose with the evap purge reg valve is connected at one end to charcoal canister the other to throttle body. The ecu controls when the evap reg valve opens. When it is open the gas vapors in the charcoal canister are sucked into the engine to be burned.
If the evap system is some how not connected to the fuel tank, when the evap purge regulator valve opened you would have a rather large vacuum leak. 
A possible cause for the unstable idle.
Here's a little tid-bit of info. On the 96 model year cars that vw put the LDP system on. They didn't activate the system, it's just there, it doesn't work. That's not "here say". That comes right out of the All Data repair manual. Which I personally think is better than the Bentely, (but costs lots more).
Intermittent sulpher smell from exhaust.
Probably the muffler.
Intermittent engine loss of power ( most likely caused from an electrical component losing voltage/voltage drops altering the fuel/air mixture.
Probably the muffler. Also check all your grounds. VWs have more problems with grounds than any other car I've worked on. 
You also mentioned checking fuel pressure (before you changed pump and filter). Have you checked it after new pump and filter? 
Don't waste money on a fuel pump relay. If the pump comes on it works.
What you described is exactly opposite of what should happen. The fuel pressure regulator has a diaphragm with a spring behind it. Also there is a vacuum line connected to the spring side of the diaphragm. When the pressure overcomes the spring the return port is opened and fuel is returned to the tank. At idle or constant load there is negative pressure acting to lessen the spring pressure on the fuel pressure reg. When the throttle valve is opened (you press on the gas pedal)there is a momentary loss of manifold vacuum. So the vacuum on the fuel pressure reg. drops making the spring pressure against the diaphragm stronger.So the fuel pressure goes up and you get a richer squirt of fuel. The same result as the accelerator pump on a carb.
So put your tester back on and see if when you press on the gas the pressure reading should go up.
Car always starts first try (though sometimes it starts up instantly, sometimes it takes a second longer if it's running like s%*t.)
Car intermittently bucks when maintaining a constant speed, *or upon deacceleration and then reacceleration.*
Check your motor mounts. The reason I say this is because of what you said about the clutch engagement changing. With a cable clutch that's the first thing I think of when the pedal goes up and down.
I hope some of this helps, I hate to think I typed all of this for nothing








Rick


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## SpeedRacer20 (Jan 7, 2004)

*Re: (R)*

Good information R, and appreciated.
One thing I do know is the buzzing in the engine bay. I know the light buzz for about 10-15 seconds is the throttle body. This buzz I was talking about was very loud, and not friendly sounding, and was only coming on during engine startup. Definetly not the throttle body.
Anyway it has stopped doing that for months so I'm not putting my efforts there.
Btw my car has the charcoal canister/evap purge regulator valve setup.
The regulator valve has been replaced and has made no differences.
At this point in time, I'm going to install the exhaust and see if all or just some of the problems have been fixed, and then will make my conclusion.
My theory is if my stock exhaust sounded all throaty and raspy and had backfire issues, then putting on the new cat-back exhaust system will HAVE to fix at least a few of my issues.
Thanks again R. I will let you know my findings.
Btw all grounds I could find have been cleaned. If you know of any out of the way, not visible grounds let me know, and I'll check those as well. But as far as I can tell, I've gotten them all.


_Modified by SpeedRacer20 at 5:49 PM 4-5-2005_


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## golf strom (Jan 14, 2002)

*Re: (SpeedRacer20)*

Hey speedracer and R,
this has to be one of the best technical threads in quite some time here on the tex. This is the kind of really helpful, very specific information that you simply can't find anywhere else, including the dealer! 
Keep up the great work guys. 
Good Luck with your situation speedracer. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
I think we should ask the moderator to put a sticky on this thread!


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## R (Oct 28, 2000)

*Re: (SpeedRacer20)*

I agree that at least some of your performance issues will be cured by the new exhaust system. Even better is the fact that you'll pick up about 10 hp in the process. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
I'm real curious about your fuel pressure. My plugs are like yours (pure white)which would seem to indicate a very lean condition. But I have toyed with the pressure to the point that I got cel for to rich and the plugs were still white as a ghost







.
When you had it scanned you say he did all the adaptations. So the throttle body check out ok?
One interesting thing I've learned about the Bosch 5.9 Motronic management system is. This system is intelligent enough to work around some failures so well that you won't realize that the component has failed. Case in point the throttle body. If the ecu doesn't get the throttle position from the throttle body. It will use the maf and engine load to calculate a value and go with that. No dtc or cel only way I knew, was that it would not do the throttle body adaptation. The car actually ran darn good, beat more than one "vtec" with it like that.
The throttle body is very sensitive to damage from welding current. So make sure if any arc welding needs to be done on your car, not only disconnect the neg battery cable, unplug the throttle body just to be sure.
Rick


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## tiohero (Sep 28, 2004)

*Re: (golf strom)*


_Quote, originally posted by *golf strom* »_
this has to be one of the best technical threads in quite some time here on the tex. This is the kind of really helpful, very specific information that you simply can't find anywhere else, including the dealer! 
thread!

I agree. It is refreshing to see a fellow tex'er put so much effort into keeping us informed instead of just letting this thread die like so many others. http://****************.com/smile/emthup.gif


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## tiohero (Sep 28, 2004)

*Re: (R)*


_Quote, originally posted by *R* »_
One interesting thing I've learned about the Bosch 5.9 Motronic management system is. This system is intelligent enough to work around some failures so well that you won't realize that the component has failed. Case in point the throttle body. If the ecu doesn't get the throttle position from the throttle body. It will use the maf and engine load to calculate a value and go with that. No dtc or cel only way I knew, was that it would not do the throttle body adaptation. The car actually ran darn good, beat more than one "vtec" with it like that.


That is some really good info! When I get my VAG-COM in the mail, that is going to be one of the first things I check for!


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## R (Oct 28, 2000)

*Re: (tiohero)*


_Quote, originally posted by *tiohero* »_
That is some really good info! When I get my VAG-COM in the mail, that is going to be one of the first things I check for!

When you get it let me know and I'll send you a label file for our 2.0L.
That will save you some of the beginners head aches with vag-com. Figuring out what the value your looking at pertains to is the biggest pita.
You will need to get a repair manual that includes the scan tool procedures. The Bentley isn't the best but it is the most available. Not the Bentley book, you need the Bentley CD. I think you can still get a bit of a break buying it from Ross tech.
Don't even bother trying to find it on the net. The licensing scheme they use is total over kill








Rick


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## thatvan (Sep 3, 2003)

*Re: (R)*

R,
What year is your car?

Speedy,
Been following along for the ride! Did you ever do the Air Valve check from a few pages back? http://****************.com/smile/emthup.gif http://****************.com/smile/emthdown.gif ?


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## R (Oct 28, 2000)

*Re: (thatvan)*


_Quote, originally posted by *thatvan* »_R,
What year is your car? 

I've got my 2 slow in a 87 jetta coupe. It's a 96. Link to pics in my sig.
Rick


_Modified by R at 12:06 PM 4-6-2005_


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## VDUBOFF (Mar 24, 2005)

Did this ever get fixed?


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## SpeedRacer20 (Jan 7, 2004)

*Re: (VDUBOFF)*

I have the exhaust installed (installation slowed down because I forgot to buy the cat to downpipe gasquet) and I will be test driving it today. Trust me I will let you know when it's fixed


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

Don't leave us hanging!


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## SpeedRacer20 (Jan 7, 2004)

*Re: (tiohero)*

OK here's the update. As you all know, the service mechanic said he could hear whistling coming from my exhaust somewhere. Due to the backfire and the exhaust note on a stock exhaust, he diagnosed that my muffler was ruined. I also had lots of pinhole size leaks from after my cat to the tailpipe.
He suggested taking off my exhaust from the cat converter back, and see if that helped anything. Well I did just that, took off the cat, the muffler and all the piping. I knew I was gonna get a CEL from there being no cat converter or cat 02 sensor. At this time I was moving, so I had a 2 hour trip to my new home to test to see if the car ran any better without a plugged muffler being on there.
There definetly was a lack of power from there being no back pressure, but overall the car seemed alot smoother, no chugging, no idle bump up and down etc. I was excited that this might fix the problem.
I went ahead and ordered the techtonics aluminized cat back system with the borla muffler. I inspected my techtonics high flow cat converter that I've been running for about 6 months, hoping that it wasn't going to be all broken up inside from my exhaust running so hot. Well, I shook the thing up and down and heard nothing loose inside. I looked inside and saw the honeycomb was a white color, but it was all intact. I figured it was still good so I installed the cat and the exhaust system with no problems at all.
I figured the CEL would turn off as soon as I put the cat/o2 sensor and exhaust on and did the steps to reset the ECU.
When all was said and done, I started the car up the car, and a bright orange CEL light stared back at me. The car sounded awesome, except for the fact it still misfired and I could still hear a whistle/whirring sound coming from somewhere.
I thought, OK I will go see my girlfriend that lives 6 hours away, and I will hope that this CEL turns off on it's own. It was freeway driving so I really pushed the car 100+mph to get every gear all the way through the RPM range.
Car misfired and did the idle dip like crazy the hole way there, the whole way back, and it's sitting in my yard now.
CEL light ON
Still misfiring
Still idle dipping
Has more overall power (was able to pull 5th gear up hills I've never been able to go up in that gear)
But still seems to run lean.
So what was really irritating me was that CEL light and why is it on.
I called up the service mechanic and asked if I could get my car in the diagnostic for free, since I've paid 2 times and never have gotten a code, and now my CEL is actually on. They agreed to let me in there for free.
So I drive my car 2 hrs back to my old town and sit in the waiting room for my diagnosis. I asked if I could talk to the mechanic as he did it, but they said they were too busy. I let it slide and just waited patiently.
30 min later the guy at the counter walked up to me and handed me a piece of paper. On it were 4 P-Codes. "P-Codes?" I thought to myself... Did they not put it on the VAG this time?
They were pretty busy at that time and didn't seem like they wanted to discuss it with me so I just took my keys and went back to my car.
The 4 P-Codes were as follows:
0141
0140
1128
1426
I have the Bentley so I went to my car and translated those P-Codes in to VAG Codes. They translated as follows:
0141= "02 Sensor Heater Circ., Bank 1 - Sensor 2 Malfunction""
0140= "02 Sensor Circ., Bank 1 - Sensor 2 No activity detected"
1128= "Long term fuel trim mult., Bank 1 System too lean"
1426= "Tank vent valve open"
He did tell me that they tried to clear the codes and it wouldn't let him.
Now this is where I'm at. When I removed the cat and rear 02 sensor, did this cause codes 0141 and 0140 to appear and now they wont go off?
Or perhaps this has been my problem all along, and maybe the 02 sensor heater relay went out (refer to code 0141) and it wasn't sending a heater signal to the 02 sensor (refer to code 0140) and that's why it's not detecting any activity. And the code 1128 (fuel trim system too lean) was a result of this.
The last code, 1426 (tank vent valve open) is a separate issue. I replaced the EVAP regulator valve a while back, so I double checked that the clamps I put on there weren't leaking. I don't know what else to check as far as that code goes.
I called up BW auto dismantlers and ordered an 02 sensor heater relay, and a new gas cap hoping this would fix both of my problems.
Replaced the old 02 sensor heat relay, and my gas cap.
No fix.
CEL light still on.
Still misfires.
Still whistle/whirring sound from the engine compartment.
Now here's my questions.
Should I dismiss the code that says my 02 sensor Bank 1 sensor 2 no activity detected because of the fact I removed that sensor when I pulled off my cat converter?
And, which sensor is it referring to by "bank 1 sensor 2"? The front o2 sensor or the cat converter sensor? I've never replaced the rear o2 sensor on the cat, I assumed they were for monitoring cat converter functionality, and not the air/fuel trim so I never bothered with it.
But if removing my exhaust that triggered that code, why am I gettinga code saying my o2 sensor relay is malfunctioning?
Can I assume that is fixed now that I've replaced that relay?
As for the Tank vent valve open code. I've never dealt with anything like this. Could someone explain to me what this code is referring to? I figured it might be the gas cap was broken, but obviously that's not the problem.
At least the car finally recognized that it was running too lean. It only took me driving it 30k miles for a CEL to come on








Sorry guys for not posting for a while, but as you can see it's quite a task tracking everything I've done to the car in proper order.
Hope you guys can help me and use this information for yourselves.
A while back I received a reply to one of my posts from a guy that owns Hillside Imports in Porland Oregon saying he knows he can fix my car.
I will be going to Portland on the 3rd of May for the Sinco de Mayo festival, and this will give me a chance to take my car to someone that hopefully knows what they are doing.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

And one other thing..
If I take my car to Portland to have Hillside diagnose it, should I worry about the 10 hour drive hurting my car? I just spend 400$ on my exhaust, and I don't want an overly lean condition messing up my resonator/borla muffler or engine internals for that matter.
I know the exhaust gets friggin' hot.
Let me know what you guys think.
If it was your car, under these circumstances, would you drive the car a possible 10 more hrs of freeway driving with it running this lean? I may not get it fixed up there, depending on what they diagnose the problem as.


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## thatvan (Sep 3, 2003)

*Re: (SpeedRacer20)*


_Quote, originally posted by *SpeedRacer20* »_
1128= "Long term fuel trim mult., Bank 1 System too lean"

Still misfires.
Still whistle/whirring sound from the engine compartment.


Sounds like you have a Major vacuum leak! Have you tried listening in the engine bay for where the whistling is coming from? For this I use a long peice of vacuum tubing to localize the sound. There is vacuum tubing that runs through the firewall so be sure to check that as well. 
I have no idea about the tank vent. Sorry. 
Recheck the connector for the rear O2 Sensor. Also make sure the wires are in good shape. If you need it I have my old O2 sensors from when I changed mine. They are still working. Send me an e-mail and I'll ship'em up to you. 
Good luck,
Ian


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## tiohero (Sep 28, 2004)

*Re: (SpeedRacer20)*

I spent some time reading through the Bentley over the past few days and I have a couple of things I can recommend...
Look on page 24a-9
Here it talks about fuel pressure tests and says specifically: "fuel pressure is a fundamental part of troubleshooting and diagnosing the Motronic system. Fuel pressure has a direct effect on fuel mixture and driveability."
Now look at page 20-2
Here is outlines some very specific proceedures for checking the fuel pump and its "delivery rate."
As Mr. Thatvan said above, you may have a major vacuum leak. I recommend that you try spraying carb cleaner around "suspect" parts of the engine (with the engine running of course). Carb cleaner will become sucked into the vacuum leak and reduce the cumbustability of the air/fuel mix. Therefore, if you spray a leaking vacuum line or a leaky intake gasket and your engine begins to sputter and maybe stall out, then you may have found the source of the leak. 
These are some tests that I plan on performing myself in the next 2 or 3 weeks.


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## Grippa (Mar 7, 2005)

*Re: (tiohero)*

I have this dang ol' bucking prob too, again.. here is my short story.
1991 16v ciiss-E monotronic.
The first time the bucking started I was also having a problem with thhe idle jumping up to about 2000, then turn it off back to normal etc. I took it to this guy in Eugene, OR. He has a shop and I think he races vw or used to or something. He checked it out, said my advance was turned way up so was my fuel and air. ( not sure exactly what that means) he said the bucking is common whenever the setting are off. So he charged me $20, anf fixed it, didn't take him long. So i got the car back, cool no problem.
drove it around for a day or two. The car was crazy slow. I mean it was coo l I guess but I couldn't stand it. He said he put it back to factory and that would solve my problems. I said well, I prefer unstable idle then it being this slow. He said he could turn it back up, but My idle would probably get crazy again. well he turned my **** up and my speed machine was back.... well a few months later and the dang thing is bucking all over the damn place. and I moved so I gottta solve it on my own. good luck to all. I don't think it is anything to major, jus a pain to those of uus who don't know. uhg.


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## tiohero (Sep 28, 2004)

*Re: (Grippa)*


_Quote, originally posted by *Grippa* »_ He checked it out, said my advance was turned way up so was my fuel and air. ( not sure exactly what that means) he said the bucking is common whenever the setting are off. So he charged me $20, anf fixed it, didn't take him long. So i got the car back, cool no problem.
.

You should have asked the mechanic exaclty what he did. It sounds to me like he may have simply advanced the timing on your car. Get a timing light and put the timing back to spec... should take no more than 5 minutes unless he did SOMETHING else... god knows what.


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## SpeedRacer20 (Jan 7, 2004)

*Re: (thatvan)*

Hey thatvan,
I've put a stethoscope down and around my engine and the piping and hoses and it's very hard to locate. The whistle noise seems to be coming from the left side of my engine, kind of around my belts. I just recently changed my belts and used belt degreaser so I don't think the belts are actually making the noise.
As for the vacuum tubing that runs through the firewall, is that the tubing that runs alongside of the coolant reservoir?
I have checked and rechecked the 02 sensor wiring and the connector. Also have cleaned the connectors with electric parts cleaner a couple times. I've never changed out the cat converter sensor, so if you have extra sensors, I'd really like to put at least the rear on.
And tiohero,
I've sprayed carb cleaner around the intake manifold of my car, but honestly I don't know where I should just go spraying that stuff. Like around my air boot and MAF? I don't want to ruin the maf if the air leak is in that area... 


_Modified by SpeedRacer20 at 6:23 PM 5-1-2005_


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## SpeedRacer20 (Jan 7, 2004)

*Re: (SpeedRacer20)*

Well here's some news guys.
After finding out that my dad has a compression tester when I saw him doing a compression check on his boat engine, I immediately got out my Bentley manual and started the compression test procedure.
The Bentley's procedure was..
Remove fuel pump fuse
Remove connector on coil
Remove all 4 spark plugs
Hook up the compression gauge
Hold the throttle wide open and let the car turn over 4-5 times.
I did the compression test and let the car turn over 4 times.
I tested each cylinder 3 times to make sure it was a stable reading.
Each "O" is a cylinder, as it would appear looking in to the engine bay.
(O)----------(O)---------(O)---------(O)
185psi-----170psi-----185psi-----185psi
Now here is the Compression Pressure Result table in the Bentley:
Engine ABA
Compression of a new engine - 145-189psi (10-13 bar)
Wear limit - 109psi (7.5 bar)
Maximum difference (I assume this means difference between cylinders...) - 44psi (3 bar)
As you guys can see, my compression pressure is awesome on all cylinders. The cylinder that tested out 170psi is well within the wear limit of 109psi, and well within the maximum difference between the others cylinders of 44psi.
This is a huge load off, I was very afraid that I had internal engine problems, like a cracked/fried cylinder, or a cracked/fried valve.
Not only are my compressions good, they are as great as a brand new engine would be.
My appointment to Hillside Imports is on Monday. I will be back on my comp about a week later and will let you guys in on the full scoop of why my car is running lean. http://****************.com/smile/emthup.gif


_Modified by SpeedRacer20 at 1:21 AM 5-2-2005_


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## thatvan (Sep 3, 2003)

So how did it go at Hillside?
Got your PM. Send another with your address if you still want me to send the sensor.


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## R (Oct 28, 2000)

*Re: (SpeedRacer20)*

The mechanic said that it wouldn't let him clear the codes? Not that he cleared the codes and they came right back.
Have you disconnected your battery for a few minutes and the codes didn't go away, even for a few seconds?
I'd pose a question in the vag-com forum about that. I've never heard of anyone having that happen.
I'd be careful spraying carb cleaner around, that stuff will eat most of the stuff it comes in contact with.
This may sound wreck-less, but another good way to check for vacuum leaks is to use a small butane torch. Open the valve on the torch but don't lite it. Then hold the torch near all your connections. If there's a leak the idle will go up.
If you think about it for a second. The butane needs to collect into a pocket in order to explode. If your outside with engine running the chances of the gas collecting anywhere is way small.
Rick


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## entrojetta (Jun 8, 2004)

*Re: (SpeedRacer20)*

May sound stupid but have you checked fuel injector plugs with a test light and the injectors themselves per bentley?


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## Pry (Nov 27, 2004)

*Re: (entrojetta)*

did this ever get resolved?


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## SpeedRacer20 (Jan 7, 2004)

*Re: (Pry)*

Sorry fellas, have been so busy with work and school it's been tough for me to contribute to my volkswagen community. Long story short, my motor mounts were jelly, causing excess engine movement and making that jerking feeling tremendous.
Hillside did a great job diagnosing, and did tests on alot of my electrical equipment making sure the resistances or whatever was all correct.
On top of the engine mounts being bad, none of the mechanics have ever actually reset the computer properly, so hillside belives that that was also making the computer and sensors to run improperly.
Something I've always thought, and I know alot of you also deal with this, in rainy weather or moist days, the car runs like it's out of breath, and seems like is has less power. Rene at hillside explained to me that this mark 3 generation has a tendency to run lean on colder days, and it's just the tendency of these cars. To know that is the cars behavior, and that it's not dying on me or parts are being damaged by a malfunction is a load off. I can live with it being tempermental, cuz when it's a nice dry warm day, the thing drives like a raped ape.
So basically, all I can recommend to you guys is:
Check your motor mounts, if they are bad buy some Turn2 motormounts, they are awesome and what I replaced my old ones with. When the motor mounts go bad, I assume they make the flexing on the down pipe die faster, that's why so many of us have problems with heatshields, rattling, and exhaust leaks.(I assume..)
Buying motor mounts makes engine respone so much better, and gives you so much more of a direct feel with your engine. Also gets rid of alot of that CHUG CHUG when you let off the pedal and gas again.
FIND A GOOD MECHANIC!!!
Find someone that knows these volkswagens, that understands the electronics on them, and they understand what resetting the god damn computer and getting rid of fault codes means.

Don't be so anal about the car.
Alot of us get way in to our cars, know every behavioral tendency of them, know when they are running good, when they are running bad etc etc. I used to get so pissed that my car runs good sometimes and not so much others but the truth is, that's just how these cars run. Tempermental.
But I still love mine


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## FL 2.0L (Aug 1, 2002)

No codes then? No CEL?


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