# Car running bad, RED HOT exhaust



## B1-16V (Aug 5, 2002)

I have been trying to fix a friends 91 Jetta. It was parked for several months. When he went to drive it last, he said it didn't have any power. It started for me, but it was very slow to rev. I shut it off and I could not get it to start for several days.
Here's a list of stuff I've done...
Static timing - Everything looked/looks good.
Changed spark plugs - one was loose.
Checked for intake blockage - no mouse nest in airbox.
Dropped cat, to see if melted down and blocking - would not start.
Did electrical tests on Digifant Harness according to Bentley - all good.
Swapped Digifant computer with one from my Golf - won't run right.
Swapped Fuel Pressure Reg with my Golf's, - no change.
Put a tester on fuel rail harness, it is pulsing, not constant on - that's good.
Compression is good, it's at 145-150 all 4.
I can SOME TIMES get the car to start, after numerous trys. The last time I tried, it was still very slow to rev, won't stay running unless hitting the gas, and I smelled something hot, saw smoke coming from the middle of the car. I looked underneath, and the pipe was completely glowing red, from the cat all the way to the muffler.
When I take the spark plugs out, 1,2,3 are sooty, and wet. #4 is clean and wet.
I have absolutely no idea what to do next.


_Modified by B1-16V at 8:26 PM 1-22-2006_


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## Banditt007 (Oct 23, 2002)

*Re: Car running bad, RED HOT exhaust (B1-16V)*

sounds like the timing is very retarded.


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## B1-16V (Aug 5, 2002)

*Re: Car running bad, RED HOT exhaust (Banditt007)*

Would retarded timing cause the glowing red? I agree, it does feel that way. When running, every once in a while it wants to kinda take off - just for a second.
How could it be so retarded if the static timing is correct? What I mean by the static timing is the cam sprocket it correct, the rotor points to the mark, the flywheel is approximately in the right spot, and the #1 spark plug cable is at the rotor.
I have an issue with the flywheel though, this car is an automatic, and there is no pointer in the window, and several dimples on the flywheel - not sure if it's truly aligned or not. BUT, the timing belt is tight, so it didn't slip - car was running in the past.
Could this be a distributor issue?
OH, by the way, the compression is good, it's at 145-150 all 4.


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## Banditt007 (Oct 23, 2002)

*Re: Car running bad, RED HOT exhaust (B1-16V)*

maybe pop out the #1 spark plug and put a dowl in there and hand turn the motor to make sure your fly wheel mark is correct. You can find TDC then, and then just look at the V cut in the fly wheel to the left of the TDC mark .
Could be off 180 degrees?
i dont really know hopefully others chime in.


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## mechsoldier (Aug 14, 2004)

*Re: Car running bad, RED HOT exhaust (Banditt007)*

You're running extremely rich, the mixture is continuing to burn in the exhaust manifold. Now you gotta figure out why.....
It could be the timing too I guess do the dowel trick to check it out.
Do you have manifold vacuum going to the fuel pressure regulator? What if you try to drive it, don't let it warm up to the point where the exhaust gets red, just try to get it into the upper RPMs and see if it runs right there.


_Modified by mechsoldier at 4:12 AM 1-23-2006_


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## kingofboggle (Mar 16, 2005)

*Re: Car running bad, RED HOT exhaust (B1-16V)*

plugged catalytic converter. innards break apart and block airflow. seen it many times before.


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## kingofboggle (Mar 16, 2005)

*Re: Car running bad, RED HOT exhaust (kingofboggle)*

get underneath car and knock on cat with a soft mallet and if you hear a lot of crusty pieces of the cat banging around, u know what you have to do next.


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## mechsoldier (Aug 14, 2004)

*Re: Car running bad, RED HOT exhaust (kingofboggle)*


_Quote, originally posted by *kingofboggle* »_plugged catalytic converter. innards break apart and block airflow. seen it many times before.

Quote Original Poster
*Dropped cat, to see if melted down and blocking - would not start.*
If he dropped the cat, the car would have ran fine if this was the problem plus he would have seen the inside broken


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## kingofboggle (Mar 16, 2005)

*Re: Car running bad, RED HOT exhaust (mechsoldier)*

sorry, skimmed over the post too quickly. i'll just shut up now


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## B1-16V (Aug 5, 2002)

*Re: Car running bad, RED HOT exhaust (mechsoldier)*

I did check the timing with an item down the spark plug hole - that checks out propper.
I'm not sure if I have vacuum to the FPR.
I only had the car running for a couple minutes, and at about 2000rpm. So I don't think a drive is possible.
I'm really leaning towards a stuck on fuel injector in #4 (at least) since, like you say, it must be running extremely rich, and the #4 plug is not fouled, it's very wet. All spark plugs are getting flame.


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## B1-16V (Aug 5, 2002)

*Re: Car running bad, RED HOT exhaust (mechsoldier)*

Yep, when the cat was down, I confirmed the interior was still intact.


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## Fox-N-It (Jul 23, 2003)

My Fox did this after my aba swap and it was a combination of vaccum leak and retarded timing.


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## B1-16V (Aug 5, 2002)

*Re: (Fox-N-It)*

I'm thinking maybe I'll try to get it to start again, with the distributor bolt loose, and advance it once it's running. I still don't get how it could have changed, since the owner said it was running fine then this.


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## The_Hamster (Jul 31, 2000)

*Re: (B1-16V)*

what do the plugs look like after you run for awhile?
runing rich means there is not enough air for the fuel provided, so it can't keep buning in the exhaust, there isn't oxygen to burn with.
lean causes it to run rather hot, and the exhaust to glow, or a pluged cat.
have you chcked the coolant temp sensor, or o2 sensors?
i'd be interested in pictures of the spark plugs if you cna get it to run for a little bit.


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## B1-16V (Aug 5, 2002)

*Re: (The_Hamster)*

#1,2,3 look black and moist. #4 is clean and moist.
I have not tried running a different Coolant temp switch. I did try running without the o2 hooked up, and the coolant temp, but no change.
Wouldn't one plug being different have to mean an issue with the injectors? Compression is basically equal all the way accross.


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## B1-16V (Aug 5, 2002)

*Re: (B1-16V)*

I am going to take out the spark plugs, turn it over, see if vapors are shooting out the holes.


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## mechsoldier (Aug 14, 2004)

*Re: (The_Hamster)*


_Quote, originally posted by *The_Hamster* »_runing rich means there is not enough air for the fuel provided, so it can't keep buning in the exhaust, there isn't oxygen to burn with.
lean causes it to run rather hot, and the exhaust to glow, or a pluged cat.

Rich mixtures up to around 9 or 10:1 can be ignited but still run like crap. 
Improper timing can cause the exhaust to glow also due to the combustion process not completing before the gasses exit the cylinder....
Lean usually won't do it because there's just a misfire in the cylinder and then that's the end of that, plus the plugs wouldn't be wet or sooty.
I changed my mind about the fuel thing though, you aren't running rich or lean, it looks like you're running rich because the timing is so messed up that you aren't completing the combustion process in the cylinder, it's in the mani.
Check and make sure that the sparkplug wires are hooked up in the right firing order and THEN check the timing again. I got twenty bucks on something is wrong with the ignition timing. Who knows what happened, but the timing is wrong.

_Modified by mechsoldier at 12:58 AM 1-24-2006_


_Modified by mechsoldier at 12:59 AM 1-24-2006_


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## B1-16V (Aug 5, 2002)

*Re: (mechsoldier)*

Ok, you win the prize - the timing is screwy. I have the car running, finally, but it's not right.
I did the fuel test, spark plugs out, terminal 3 and 13 bridged (pump running). I looked down the holes, no gas vissible. We can eliminate the injector theory.
I just started moving the distributor (advance) a bit at a time, and if finally started. So I get the thing running, no more glowing exhaust.








Problem is it will only run with a WHOLE LOT of advance. My timing light with dial was dialed to around 50 advance. 
(yes, I am doing the Digifant timing correctly - Coolant switch plug off, 2200 rpms, revved to clear etc...)
So I thought I'd look at cam timing again, decided it was 1 tooth advanced, based on putting a skinny object down #1 for TDC.
*Problem is I still don't know for sure where to put an automatics flywheel - there seems to be several marks*. So, honestly, I'm just guessing the best I can with the hieght of the piston.
Still, it will only run at about 45 advance. It's running, but not smoothly, but it will rev.
Here's another clue - on my good working Golf, when connecting the coolant plug, the timing will change. This Jetta will not do that. OH, and also, no change depending on rpm - that whole Digi timing routine doesn't seem to matter to this car.
Do I have a distributor issue?
Is it time to swap my good computer in again?


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## Banditt007 (Oct 23, 2002)

*Re: (B1-16V)*

instead of trying to find TDC on the flywheel. go to the crank shaft pully, and there should be a notch cut out on it (small) like a line. That should line up with an arrow that is on the belt splash cover directly above the pully. that is TDC. THen you can go to your flywheel and mark it directly below the arrow that is cast into the housing of the tranny case.


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## B1-16V (Aug 5, 2002)

*Re: (Banditt007)*

I was looking through the wrong window. I had no idea there was another window, it was covered with wire harnesses








Even though I was looking through the wrong window, it still checks out on static timing - it was dead on. The marks I could see through the first window (towards the back of the bell housing) can not be seen in the window with the pointer, and vice versa - windows are offset. Remember, this is an automatic tranny, I've never even seen an A2 automatic before.
SO, with static timing good, it will not run at anything less than about 40 degrees advance.
Someone here has got to know why the timing doesn't change when removing the coolant temp harness, or changing rpm. 
Every other car will change timing when rpms change


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## Banditt007 (Oct 23, 2002)

*Re: (B1-16V)*

sorry didnt know it was an automatic, i have no expereince with them.
ECU is shot maybe? thats what would control the the timing to change during revs. By using the knock sensor, coolant temp sensor, and hall sensor.


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## B1-16V (Aug 5, 2002)

*Re: (Banditt007)*

I switched the ecu with the one from my car. No change.
Can the hall sensor in the distributor be bad? I tested the wires going to it, they're fine, but I see no test in the Bentley for the Hall sensor.
I'm now thinking of puting my distributor in this car.


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## onewiper (Aug 29, 2002)

Not sure if you have knock sensor but if you do I would suspect a faulty ks unit.


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## Banditt007 (Oct 23, 2002)

*Re: (onewiper)*


_Quote, originally posted by *onewiper* »_Not sure if you have knock sensor but if you do I would suspect a faulty ks unit.

THis is a good point i didnt think of. Knock sensor definitly retards the timing. However i believe if it is disconnected the ECU reverts to a 'safe' timing map, which would make the car slower ect but shouldnt run as bad as its sounding it is.
However its possible that the KS is just sending false information and thats whats messing it up, but even at that i think no matter what the info from the knock sensor that is sent to the ECU it can only retard the timing so much. Also i think it actually has to get up to a certain temperature before it should work (normally) Or the ECU has to see that the coolant temp is at a certain temp or above. I know there is something to do w/ temperature when dealing with the knock sensor.


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## B1-16V (Aug 5, 2002)

*Re: (Banditt007)*

I tried puting my good distributor in this car, didn't start. I put the Distributor from the bad Jetta in my Golf, it ran just fine.
So, we can now rule out...
Computer
Distributor
Anything fuel related.
But the KS is interesting.


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## The_Hamster (Jul 31, 2000)

*Re: (mechsoldier)*


_Quote »_Rich mixtures up to around 9 or 10:1 can be ignited but still run like crap. 

yes, but they do not run hot. the excess fuel has a cooling effect on the chamber. some cars use a slightly rich mixture from the factory to keep combustion temps down, such as the srt-4.


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## debssmith1990 (11 mo ago)

B1-16V said:


> I have been trying to fix a friends 91 Jetta. It was parked for several months. When he went to drive it last, he said it didn't have any power. It started for me, but it was very slow to rev. I shut it off and I could not get it to start for several days.
> Here's a list of stuff I've done...
> Static timing - Everything looked/looks good.
> Changed spark plugs - one was loose.
> ...


If your exhaust manifold is getting hot you might have a leaking injector or your air intake manifold gasket is not sealing therefore making it rich as I've got that problem just waiting on parts


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## Butcher (Jan 31, 2001)

Rich fuel mixtures run colder. About as cold as this 16 year old thread.


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