Crazy Misfires (No, its not the same ol shit)

[Militant-Grunt]

2001 AWM 1.8t

So for the past month I have been trying to figure out why my car is misfiring. The car upon cold start up misfires and does not register the misfires within the ECU. Upon warm up, at half throttle car will also misfire and then stop. At WOT, occasionally car will cut 100% throttle, and misfire terribly.

What I have done so far:
4 new coil packs
Maf
Running virtually new F5DPOR Sidefires (Also tried BKRE6s and BKRE7's gapped at .028)
Front 02
Replaced all rubber that carries vacuum, this baby is as tight as a whistle no boost leaks.

My car has the evap simplification mod, and a few bolt ons, running a custom SSP tuned with mbc @ 20psi. (And no its not the tune because it does the same shit on a stock file).

Here is a screen shot of the log I took of Blocks 002, 020 and 031
Car has some CRAZY injector pulse times. Another thing is I have had this problem for a while, it went away when I had a misfire code stored on the ecu, car ran beautifully for a month (Car ran so well infact it posted the fastest CAPS time for a k03 car. (6.14)), and one night when I cleared the code, the exact problem came back.








The motor is going in for a build regardless, but its not a problem I want to possibly carry over to my next setup.

[TverRus69]

idk about how exactly the coils connect to the plugs in the 1.8, but the 2.8 has harnesses that can get fed up... this may be completely not applicable to 1.8s tho. Just a thought. Besides that could it be the injectors themselves?
The MAF/Injector numbers dont match up...

[2001S4NY]

might be injectors since i think the took a dive under water a while ago :P

[zrowcool]

fuel line/pump okay? i kinked a line once installin the fuel filter and had similar symptoms

[97YellowA4]

i dont know but maybe it could be a valve cover gasket. oil getting into your spark plug hold.i had symptoms like that.

[Seerlah]

Try Lucus fuel injector cleaner.

[prodrive]

I would check each coil resistance by an avometer.

[turbo kraut]

might be off the wall and way out of the ball park, but i had some misfiring and stuff

and it was my crank position sensor..... replaced that car ran fine

[Militant-Grunt]

i dont know but maybe it could be a valve cover gasket. oil getting into your spark plug hold.i had symptoms like that.

I tried 2x lucas fuel injector clear, I seafoamed the car, and I did the valve cover gaskets over the summer, the plugs are not fouled. Someone on vwvortex deducted that the car is running very lean.

[Tifun]

if you can vagom do that and see which cylinders are missing when. Might help you marrow it down

[Militant-Grunt]

if you can vagom do that and see which cylinders are missing when. Might help you marrow it down

Tried that, vagcom has misfire recognition OFF for whatever reason, I drive around with a laptop of my knees and vag com open trying to figure out wtf is going on with my car.

[calibroha]

2001 AWM 1.8t

So for the past month I have been trying to figure out why my car is misfiring. The car upon cold start up misfires and does not register the misfires within the ECU. Upon warm up, at half throttle car will also misfire and then stop. At WOT, occasionally car will cut 100% throttle, and misfire terribly.

What I have done so far:
4 new coil packs
Maf
Running virtually new F5DPOR Sidefires (Also tried BKRE6s and BKRE7's gapped at .028)
Front 02
Replaced all rubber that carries vacuum, this baby is as tight as a whistle no boost leaks.

My car has the evap simplification mod, and a few bolt ons, running a custom SSP tuned with mbc @ 20psi. (And no its not the tune because it does the same shit on a stock file).

Here is a screen shot of the log I took of Blocks 002, 020 and 031
Car has some CRAZY injector pulse times. Another thing is I have had this problem for a while, it went away when I had a misfire code stored on the ecu, car ran beautifully for a month (Car ran so well infact it posted the fastest CAPS time for a k03 car. (6.14)), and one night when I cleared the code, the exact problem came back.








The motor is going in for a build regardless, but its not a problem I want to possibly carry over to my next setup.

i know this sounds stupid.. but have you checked to see if any of the wires are arching?
my car was just recently misfiring like crazy and kinda sounds like your same problem..
i was with a friend i met thru the forums and we were under the hood looking as the car was running, after switching out injector after injector ((cause thats what my last misfire was)) we saw a very very small spark coming from a wire that was leaning up against the intake manifold, that had melted thru so the spark was grounding out on the manny before it ever got to the spark plug..
yup we're geniuses
just my 2cents, you never know..

[calibroha]

haha i didnt even read what anyone else wrote, but when i was posting and talking to people all the things everyone is saying was said to me and i tried all of them.. crazy i feel like im having dejavu

[Tifun]

Tried that, vagcom has misfire recognition OFF for whatever reason, I drive around with a laptop of my knees and vag com open trying to figure out wtf is going on with my car.

It should enable itself once the vehicle is under load. It's kinda hard to watch it and drive at the same time. I suggest a passenger haha.

[bigrobby]

1. I don't know about the MAF/Injector match.....but it sounds like the symptoms aren't consistent (correct me on that OP if i'm wrong)

2. I've seen the crank sensor cause really weird problems. That would also explain weird injector times. doesn't happen often though.

3. you replaced the MAF....not just cleaned... it right?? just thought i'd check.

4.Did this start randomly one day....or after you changed something?

5. I've seen fuel turned to gel crud cause this problem...it got in everything. but that A4 sat for a year with a low tank then someone took it out and ran it on empty. and i saw you did seafoam but so did we. we just swapped almost every fuel part with a parts car.

6. I can't imagine erasing the misfire code actually caused it to run poorly again. someone correct me if i'm wrong. (((unless..i dont know this....but will some codes cause the car to run on open loop....meaning not using the oxygen sensor for mixture control))) I've had a bad O2 sensor cause weird things on other cars.... ( i know you said you replaced it ...but maybe something on the ECU side of the connector causing a weird signal. not likely.

[Militant-Grunt]

1. I don't know about the MAF/Injector match.....but it sounds like the symptoms aren't consistent (correct me on that OP if i'm wrong)

Its pretty consistent in the instances where I mentioned the misfires occurring.

2. I've seen the crank sensor cause really weird problems. That would also explain weird injector times. doesn't happen often though.

I'll give that a try, I'm also going to order a coil pack harness.

3. you replaced the MAF....not just cleaned... it right?? just thought i'd check.

Previous owner has, disconnecting the MAF doesn't help though, so its DEF not that.

4.Did this start randomly one day....or after you changed something?

Randomly

5. I've seen fuel turned to gel crud cause this problem...it got in everything. but that A4 sat for a year with a low tank then someone took it out and ran it on empty. and i saw you did seafoam but so did we. we just swapped almost every fuel part with a parts car.

The car wasn't really sitting, I lucas'ed it and seafoamed it.

6. I can't imagine erasing the misfire code actually caused it to run poorly again. someone correct me if i'm wrong. (((unless..i dont know this....but will some codes cause the car to run on open loop....meaning not using the oxygen sensor for mixture control))) I've had a bad O2 sensor cause weird things on other cars.... ( i know you said you replaced it ...but maybe something on the ECU side of the connector causing a weird signal. not likely.

Haha believe it. My 02 voltage is at 1.5v.

[Militant-Grunt]

Bump for ideas.

[zrowcool]

im gonna again vote for fuel... check the filter, the injectors, the harness, and the lines. it would make sense of the lean condition and the cutting throttle as well as the misfiring. i had a kinked fuel line causing very similar symptoms. log the injector cycle block all the way to WOT where you're having the issue. i dont know what block it is but im sure you're more familiar with vag-com than me

[belinko]

Possibly EGR valve?

[bigrobby]

to be honest.....when we have problems this annoying and with this many possibilities.....it's when you need to find a friend. find a friend with the same car and start swapping parts.

we can guess and speculate......and you can spend money on parts all day....but just start swappin crap. if only you lived in atlanta i could get ya a 2001 for swappin

[Militant-Grunt]

Possibly EGR valve?

Mine has been removed, I have the evap simplification mod done. I have a sai block off plate in place of the egr.

[Militant-Grunt]

to be honest.....when we have problems this annoying and with this many possibilities.....it's when you need to find a friend. find a friend with the same car and start swapping parts.

we can guess and speculate......and you can spend money on parts all day....but just start swappin crap. if only you lived in atlanta i could get ya a 2001 for swappin

Thanks for the offer, my problem is all my friends drive 2.7t's haha.

I will be stealing a friends Map sensor to see if mine is faulty. I also have a cam position sensor from an s4 to try out.

[Tifun]

Bump for ideas.

Did you see my post about the enable? Just curious is all. I also have a hex-can vagcom depending on what version you have I suppose it may not be accessable. I still think yo need to see if you can narrow it down to a particular cylinder. Another random thought might be a fueling issue. I don't know if it's possible or the same as with my old Nissans. I use to max injectors out all the time and the car would randomly misfire at idle and do it at wot as well. That or a fuel pump getting weak.

[Militant-Grunt]

Today in the morning it was misfiring a lot, I finish work, get into the car, drive, no misifires, no matter how much I floor it, I guess the code I used to have it back stored in the ECU, ill update tomorrow once I pull the code.