# Cylinder 1 misfire when cold, once warmed up it goes away (AWP)



## jkcorradovr6 (Mar 13, 2002)

OK guys need some help here as I'm loosing my mind.

Car in question is a MK4 1.8T AWP.

Problem: At start up, car has a constant misfire on cylinder #1. As I watch misfire detection with vagcom it goes up in the the hundreds and continues to misfire. When the car is revved while still being cold the misfires drastically decrease to almost stop. Now once the temp reaches approx 90 degrees Celsius the misfire in cylinder one goes away completely and the car runs great. I clear the code and drive it around and no more misfires in #1 will pop up.

History: The car broke a timing belt and sat for a few months. Cylinder head was rebuilt and fitted with new T-belt and water pump, HG, head studs and according gaskets. 

Parts: Besides the above parts mentioned the car has new OEM NGK spark plus, new PCV system, CTS, and fuel filter.

What I have done with no change: Re-gapped spark plugs, swapped plugs, swapped coil packs, swapped injector wiring between 1 and 2, checked for boost leaks, tested for 12V coming out of coil pack harness and I'm sure there's more I am forgetting.


So with all that said does anyone have any insight on what this problem could be? I feel like I just need to take a break from it and collect some advice.

Thanks


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## vwdmach (Jul 17, 2008)

*wat mods?*

what mods do you have done to the vehicle? I had an issue like this with my awp GTI, but I started off with a cylinder #2 misfire and then ended up leading to random misfires from all cylinders and it would only do it on cold starts, and I basically did the same stuff you did with putting new plugs and coils and swapping plugs and so on. I also do have every modification done to my car that you can do before going big turbo.(Full 3" TB, TIP, FMIC, Forge splitter DV) I got so sick of not being able to find the problem after replacing sensors after sensor that could of caused the problem, then i finally just decided to put all my stock parts back on, and the first thing I did was put the stock DV back on clear the check engine and see how the car ran for a few days. And wata you know I had a defective Forged DV that was causing my whole problem. It just sucks becuz there are so many thing on the AWP that can cause a misfire on cold starts. You could also check your PCV and all the hoses(they crack after awhile), the air pump also if its working properly when you first start your car.


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## groggory (Apr 21, 2003)

I'd like to see what your fueling looks like.

Let the car warm up to at least 87C, then do a 3rd gear WOT pull from 2k-5500 logging blocks 1,31,32


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## Vegeta Gti (Feb 13, 2003)

dont ever "let" the car warm up..drive it immediately.

j, what plug gap? is it flashed? it's ok to go a temp range down on stock if not flashed and a solid gap is .28 for flashed and stock, though i prefer lower.

were all the valves new? were they lapped into the seats?

how is your coolant temp sensor? thermostat stuck open?


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## jkcorradovr6 (Mar 13, 2002)

Thanks for the reply guys:

This cars is currently bone stock. The only mods it ever had we're a Forge DV and CAI. But they have been removed for stock parts. 

Mach: I will try some of those things car did have a forge DV on it before head job so I'll try putting it back on. Also the PCV system is brand new bc I did find some cracks in it. 

Grog: I will get some logging done for sure just tell me anything else you guys may wanna see. 

Chris: I've had the gap at 32 29 and currently at 27. Obviously seems a bit better at 27. Only valves that had to be replaced were cylinder 3 exhaust valves. They were brand new when replaced. I'm not sure by what you mean to not let it warm up. This car just misses until about 90 degrees cel. I replaced the CTS with no change but have not looked into the thermostat.


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## Chickenman35 (Jul 28, 2006)

1: Could be a bad injector in #1 cylinder. They can be intermittent. Physically remove the injector and swap it out to another cylinder. See if the misfire follows injector. If it does you've found your culprit.

2: Don't overlook the problem of a bad ignition harness. Cracked and frayed wires can wreak havoc. A simple 12v check is not enough. You must physically check the wires for cracks and bare wires. The coil trigger wires are very sensitive to EMI. Cracked harnesses can dramatically increase EMI.

3: Coil packs may also be getting weak. Cold engines place more demands on ignition system. 

Check above items in order...but check them all. Could be one problem or a combination of problems adding up.


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## Chickenman35 (Jul 28, 2006)

BTW...I don't quite follow what you mean by swapping the injector wiring between #1 and #2??


The fuel injection on these engines is sequential...not batch fire. If you switched the injector terminals between #1 and #2 then the injectors would be firing at the wrong time. At high RPM this may not make much difference ( Since injectors are effectively wide open and intake tract is virtually filled constantly with a fuel/air mix )...but at idle and low RPM the injector timing pulses would be off.

Am I missing something here????


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## groggory (Apr 21, 2003)

When switching injectors, replace ALL o-rings. Make sure to lube them with dielectric grease before reseating them


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## jkcorradovr6 (Mar 13, 2002)

Chickenman35 said:


> BTW...I don't quite follow what you mean by swapping the injector wiring between #1 and #2??
> 
> 
> The fuel injection on these engines is sequential...not batch fire. If you switched the injector terminals between #1 and #2 then the injectors would be firing at the wrong time. At high RPM this may not make much difference ( Since injectors are effectively wide open and intake tract is virtually filled constantly with a fuel/air mix )...but at idle and low RPM the injector timing pulses would be off.
> ...


You're right I think I had just been working on this for two long and started to loose my mind with frustration. I will physically swap injectors and report and continue with the next step if needed.


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## Vegeta Gti (Feb 13, 2003)

what i mean is idle after cold start. Vw has stated in the owners manual for over 50 years...do not idle for warm up, drive gently.

anyway, it is probably something minor. vacuum leak on an injector, etc.
move the coil to #3 see if the misfire moves.
wouldn't hurt to do a leak test....could spray around #1injector and such with brake clean when cold..it will stumble hard f you find a leak.


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## Vegeta Gti (Feb 13, 2003)

to elaborate on teh warm up..

think fo the heat that is instantly transfered into all the metal, into the oil much faster and coolant much faster under actuall light, moving load. quick heat up with easy driving, sustained oil pressure that is absorbing heat...common sense...only other option is a block heater to maintain fluid and material heat.

sorry to sidetrack bro


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## jkcorradovr6 (Mar 13, 2002)

Vegeta Gti said:


> what i mean is idle after cold start. Vw has stated in the owners manual for over 50 years...do not idle for warm up, drive gently.
> 
> anyway, it is probably something minor. vacuum leak on an injector, etc.
> move the coil to #3 see if the misfire moves.
> wouldn't hurt to do a leak test....could spray around #1injector and such with brake clean when cold..it will stumble hard f you find a leak.


I have swapped coils with no change and checked for vacuum leaks as to why I ended up replacing the PCV system. Also sprayed brake clean just about everywhere. I am going to swap injectors and see the results.


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## groggory (Apr 21, 2003)

jkcorradovr6 said:


> I have swapped coils with no change and checked for vacuum leaks as to why I ended up replacing the PCV system. Also sprayed brake clean just about everywhere. I am going to swap injectors and see the results.


FYI, the only way to check for vac leaks that actually works on this car is to pressure test per the sticky at the top of the forum.


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## jkcorradovr6 (Mar 13, 2002)

OK, so I just swapped injectors between cylinder 1 and cylinder 2. The constant misfire continues in cylinder 1. 

I did also notice that while cylinder one is constantly misfiring, if I unplug cylinder 1 injectors the car runs worse, but if I unplug cylinder 1 coil pack plug while misfiring it runs the same.

Is there a missing link here? 

Once the car reaches 90 degrees celcius it runs fine.


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## groggory (Apr 21, 2003)

jkcorradovr6 said:


> if I unplug cylinder 1 coil pack plug while misfiring it runs the same.
> 
> Once the car reaches 90 degrees celcius it runs fine.



Swap coil packs on cyl 1 and cyl 4. See what happens.


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## jkcorradovr6 (Mar 13, 2002)

groggory said:


> Swap coil packs on cyl 1 and cyl 4. See what happens.


Same. Still cylinder 1 misfire.


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## groggory (Apr 21, 2003)

Could you post two sets of logs...


Idle when cold
blocks 1,31,32

Idle when up to temp, block 1 should show coolant >87C
same blocks

WOT pull, 3rd gear, 2k-5k
same blocks

Don't edit the logs, just post em up and I'll figure out what to do with them.


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## jkcorradovr6 (Mar 13, 2002)

groggory said:


> Could you post two sets of logs...
> 
> 
> Idle when cold
> ...


Awesome thanks! I'll get on that in the AM.



Also I just untaped pretty much the entire wiring harness and all the wires looked great. Nothing broken, kinked, or exposed.


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## Chickenman35 (Jul 28, 2006)

jkcorradovr6 said:


> (Snip)
> I did also notice that while cylinder one is constantly misfiring, if I unplug cylinder 1 injectors the car runs worse, but if I unplug cylinder 1 coil pack plug while misfiring it runs the same.
> 
> Is there a missing link here?
> ...


Well that just doesn't make sense at all!! 

In addition to what Groggery has requested, post up a complete VAG-Scan. Pull the plugs, lay them out in order and take a picture of them. 

Might be a good idea to do a compression test while plugs are out. Do that when engine cold and then when fully warm. Compare the two figures ( cold and hot ) for any anomalies .

Be sure that you disconnect all injector terminals and jam the throttle wide open with a screwdriver.


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## groggory (Apr 21, 2003)

For plug pics

No flash
Good lighting
On white background (paper towel)


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## jkcorradovr6 (Mar 13, 2002)

Did a compression test before I even started the car for the day and after it warmed up. The results were 180psi across all cylinders both hot and cold.










I don't think I'll be able to do the logging until Tuesday as I got side tracked with work.

Also I will get pics of the plugs. I have had them all out before and number one plug center electrode is completely brownish and "fowled" compared to the rest which are perfectly clean. 

Hopefully you guys can bear with me until Tuesday.

I really appreciate all the help.


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## jkcorradovr6 (Mar 13, 2002)

Finally got some time to work in the car below is the complete Auto Scan:

(Logging coming shortly)

Thursday,22,November,2012,12:51:02:63549
VCDS Version: Release 11.11.4
Data version: 20120807


Chassis Type: 1J - VW Golf/Bora IV
Scan: 01 02 03 08 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57 75
76

VIN: 3VWSE69M44M142709 Mileage: 248030km/154118miles
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Address 01: Engine Labels: 06A-906-032-AWP.lbl
Part No: 06A 906 032 RN
Component: 1.8L R4/5VT G 0001 
Coding: 07510
Shop #: WSC 00066 
VCID: 7BFE7242691D5DC0747
3VWSE69M44M142709 VWZ7Z0D9666401

2 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected 
P0300 - 35-00 - 
16685 - Cylinder 1 
P0301 - 35-00 - Misfire Detected
Readiness: 0010 1101

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 1C0-907-37x-ESP-F.lbl
Part No: 1C0 907 379 M
Component: ESP FRONT MK60 0102 
Coding: 0019970
Shop #: WSC 00028 000 00000
VCID: 346C997E54C352B8F5D

1 Fault Found:
01314 - Engine Control Module 
013 - Check DTC Memory - Intermittent

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 1C0 909 605 F
Component: 04 AIRBAG VW61 0202 0003 
Coding: 12340
Shop #: WSC 00028 
VCID: 27567E32C515292040F

1 Fault Found:
00532 - Supply Voltage B+ 
07-10 - Signal too Low - Intermittent

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J5 920 926 H
Component: KOMBI+WEGFAHRSP VDO V55 
Coding: 15230
Shop #: WSC 00000 
VCID: 346C997E04C352B8F5D
3VWSE69M44M142709 VWZ7Z0D9666401

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.lbl
Part No: 6N0 909 901 
Component: Gateway KCAN 0001 
Coding: 00006
Shop #: WSC 00028 
VCID: F0E4D56EB05BAE98515

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 1C0-959-799.lbl
Part No: 1C0 959 799 C
Component: 1H Komfortgerát HLO 0003 
Coding: 00258
Shop #: WSC 00028 
VCID: 3776AE7215B5B9A0D0F

Subsystem 1 - Part No: 1C1959801A
Component: 1H Tõrsteuer.FS KLO 0202 

Subsystem 2 - Part No: 1C1959802A
Component: 1H Tõrsteuer.BF KLO 0202 

Subsystem 3 - Part No: 1C0959811A
Component: 1H Tõrsteuer.HL KLO 0202 

Subsystem 4 - Part No: 1C0959812A
Component: 1H Tõrsteuer.HR KLO 0202 


No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio Labels: 3B7-035-1xx-56.lbl
Part No: 3B7 035 180 G
Component: Radio ZSW 0016 
Coding: 00031
Shop #: WSC 00028 
VCID: 244C693EB423C23865D

No fault code found.

End ---------------------------------------------------------------------


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## jkcorradovr6 (Mar 13, 2002)

OK this posted is dedicated to the Logs of groups 001-031-032 when engine is COLD:


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## jkcorradovr6 (Mar 13, 2002)

This posted is dedicated to the Logs of groups 001-031-032 when engine is WARM:


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## jkcorradovr6 (Mar 13, 2002)

This posted is dedicated to the Logs of groups 001-031-032 at WOT from 2k-5k RPM:


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## jkcorradovr6 (Mar 13, 2002)

TTT


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## jkcorradovr6 (Mar 13, 2002)

:thumbup::thumbup::thumbup:


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## thefrese (Mar 8, 2012)

After the timing belt broke and the head was rebuilt you are CERTAIN there was no remaining piston/valve damage? Was the motor cold or warm when you did the compression test? I can't imagine another reason the misfire would stay on cyl1 after swapping around injectors and coils.


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## groggory (Apr 21, 2003)

thefrese said:


> After the timing belt broke and the head was rebuilt you are CERTAIN there was no remaining piston/valve damage? Was the motor cold or warm when you did the compression test? I can't imagine another reason the misfire would stay on cyl1 after swapping around injectors and coils.


I had that problem once. Ended up I was running super rich and oxygen sensor was shot. Misfires predominately showed up in cyl 1


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## radlynx (Jan 4, 2007)

so, what's your verdict? did you fix this yet?



jkcorradovr6 said:


> OK guys need some help here as I'm loosing my mind.
> 
> Car in question is a MK4 1.8T AWP.
> 
> ...


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## jkcorradovr6 (Mar 13, 2002)

Compression test was done when cold (let car sit over night) and when at operating temperature. Both showed results of 180psi. The post goes over everything I have tried in detail. 

I have not had much time to worker on her the last two weeks and have not found a solution. 

I have searched and found 2 other similar post. One had no solution and the other the person replaced the lifters and it fixed the problem.


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## jkcorradovr6 (Mar 13, 2002)

ttt


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## Beniamin (Feb 10, 2011)

I have the same problem. In for answer.


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## jkcorradovr6 (Mar 13, 2002)

Beniamin said:


> I have the same problem. In for answer.


In cylinder one as well?


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## jkcorradovr6 (Mar 13, 2002)

PS: Also not sure if I mentioned that the misfires are rapid in cylinder #1. The counter goes up to 300+


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## jkcorradovr6 (Mar 13, 2002)

still can't figure this out


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## Slimjimmn (Apr 8, 2006)

This sounds like a telltale failed head gasket IMO.


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## groggory (Apr 21, 2003)

Slimjimmn said:


> This sounds like a telltale failed head gasket IMO.


 Leakdown test can confirm this


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## meandubbin (Dec 2, 2010)

I am having the same issues after a timing belt change and my misfire is in cylinder 4 have you fixed this problem yet


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## meandubbin (Dec 2, 2010)

bump it again


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## GLI_jetta (Jan 3, 2006)

groggory said:


> Leakdown test can confirm this


I was just going to say... that imo is the next logical step. Close the valves on cylinder 1 and leak test it.


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## meandubbin (Dec 2, 2010)

i have already done this and i need some more insight i've been trying to do all i can before pulling the head and getting it decked and then put back on and still having this problem....:banghead:


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## GLI_jetta (Jan 3, 2006)

if you leaked down the cylinder and didnt find the head gasket blew or the head was leaking at all, having it decked wouldnt do anything I dont think...


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## Slimjimmn (Apr 8, 2006)

What were your percent readings on the leak down test!


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## meandubbin (Dec 2, 2010)

i wasnt saying that getting the head decked would fix it. im saying that its coming down to pulling the head to see if anything wrong with it


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## taverncustoms (Feb 18, 2011)

any chance you have a bad gasket between the intake manifold and head? any way to pressure test the manifold when cold? 
Have you checked for injector signal at the injector connector? and at the coil connector? 
just because swapping the coil or injector dose not change the issue, does not mean the electronic signal is good. you may have a wiring issue or ecu problem. good luck


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## taverncustoms (Feb 18, 2011)

sometimes you can test the injector via a scan tool and a fuel pressure tester. you can pull the coil and use an old school spark tester with the light and see if its firing every time.


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## meandubbin (Dec 2, 2010)

http://forums.vwvortex.com/showthre...r-4-need-some-help!!!&p=80584738#post80584738 

That is the link to my problem if you care to read it it shows everything that has been done


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## kamahao112 (Nov 17, 2007)

jake have you checked the coil harness it self ??


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## meandubbin (Dec 2, 2010)

My under pants look like the third turn at the Indy 500


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## [DubSTeR]01 (Nov 13, 2002)

your saying that this only happens on cold start ups and is fine after it warms up?

that sounds like either something is leaking into the cylinder overnight and it's burning it off in the morning witch is giving you the misfire.

Or the is a air leak somewhere, because as the car cools down all the gaskets/O-rings shrink thus creating a vacuum leak. easy way to check for a leak is to spray some sort of hydrocarbon around all gaskets and O-rings and listen for engine to change idle/running condition.
then repair said leak.


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## Slimjimmn (Apr 8, 2006)

aka head gasket


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## meandubbin (Dec 2, 2010)

Any progress???


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## Beniamin (Feb 10, 2011)

TTT. Same issue on cylinder 1,3,4. Changed coil packs 7,000 Miles ago. Harness is good. If the head gasket was bad, wouldn't there be oil in the coolant? Also, Vag-com said it might be the coolant sensor, I've replaced it three times. I'm still stuck.. :facepalm:


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## [DubSTeR]01 (Nov 13, 2002)

there doesn't have to be a coolant/oil mix for there to be a bad head gasket,
I would find a shop that has the tool to test for hydrocarbons in your cooling system. it's like a baster thing with blue fluid in it that changes colour with the presence of hydrocarbons. this will tell u if there is a head gasket problem


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## Twopnt016v (Jul 5, 2009)

I'm with Slimm...headgasket.


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## meandubbin (Dec 2, 2010)

ok so can you both explain how it would be a headgasket? if theres no white smoke or blue smoke or lose of coolant or oil


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## groggory (Apr 21, 2003)

groggory said:


> Leakdown test can confirm this


Head gasket is our best guess...and this is a relatively easy test that can confirm or refute it. Seems straight forward enough for me.


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## jbutlertelecom (Aug 12, 2009)

I would think this is indicative of a cracked exhaust manifold. I had a similar cold start misfire on cyl #2 when I ran the Kinetic manifold on a K04-015 turbo. This is what I found:



















The manifold was cracked from the collector all the way down the cyl 2 runner and almost to the flange. Once replaced the misfire went away.
Ymmv

Good luck


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## groggory (Apr 21, 2003)

jbutlertelecom said:


> I would think this is indicative of a cracked exhaust manifold. I had a similar cold start misfire on cyl #2 when I ran the Kinetic manifold on a K04-015 turbo. This is what I found:
> 
> 
> 
> ...


Would this sort of crack show up with a seafoam test?


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## jbutlertelecom (Aug 12, 2009)

groggory said:


> Would this sort of crack show up with a seafoam test?


Doubtful. Seafoam requires the engine be up to temp in order for it to work (smoke/steam clean). The crack will be sealed up at that point and the leak will be hard as hell to find. Longitudinally mounted engines block the underside view of the manifold with the turbo installed, transverse would be easier to see in the installed position from underneath. YMMV


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## meandubbin (Dec 2, 2010)

i have done a leak down test and a compression test hot and cold and everything checks out. 
and my misfire will stay constant now even when warmed up but if i shut the car off and turn it back on the misfire goes away and the car runs fine :banghead:


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## Slimjimmn (Apr 8, 2006)

meandubbin said:


> ok so can you both explain how it would be a headgasket? if theres no white smoke or blue smoke or lose of coolant or oil


head gasket can leak many ways

1- oil to coolant
2-coolant to combustion = rough idle cold, warm ok
3-oil to combustion
4-external leak
5-compression ring failure = low compression when cold, ok when warm


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## meandubbin (Dec 2, 2010)

ok well riddle my this batman? I've done a couple oil changes with the car running like this and a I've got a bank 1 camshaft over retarded code. is that normal?:banghead:


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## Slimjimmn (Apr 8, 2006)

No. Any engine codes are not normal dude


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## Twopnt016v (Jul 5, 2009)

Sounds to me like you need to focus on the timing code first and foremost. Get that resolved and then and move forward from there. I'd pull the VC and check cam timing as well as cam to crank.


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## meandubbin (Dec 2, 2010)

:banghead:cacabox


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## Beniamin (Feb 10, 2011)

Any new info?


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## fingerlakes (Apr 9, 2013)

meandubbin said:


> :banghead:cacabox


So did you figure this out? I have the exact same problem with cyl 4 on my CC 2.0T - Changed all coil packs and plugs. Also did a CRC cleaning. Misfires on cold start usually when colder outside - is fine when it's up to temp. When I notice it misfiring I turn of and then back on and it seams to go away.. it's bizarre. Thanks!


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