I have searched, I have bought a vagcom finally, and I have logged. Here are my symptoms

- Never a problem at idle, perfectly smooth
- Under hard acceleration, or partial throttle engine suffers heavy misfires
- sometimes (1/4-1/3) of the time the car pulls hard and like a champ, right up to the redline as if there is absolutely nothing wrong
- HATES to be idled, drives like complete crap if it sits too long
- Boost is very spikey, or punchy at times


Under an engine scan (same codes keep popping up):

6 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16687 - Cylinder 3: Misfire Detected
P0303 - 35-00 - -
16686 - Cylinder 2: Misfire Detected
P0302 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
P0301 - 35-00 - -
16688 - Cylinder 4: Misfire Detected
P0304 - 35-00 - -
17536 - Fuel Trim; Bank 1 (Mult): System too Lean
P1128 - 35-00 - -

Readiness: 0010 1001
---------------------------------------------------------------------------


Notables from logging:
- I can't do a full WOT pull, engine goes into severe misfires but I was able to gather the following:
- EGT are normal, max I logged was around 630C
- At idle everything is normal
- coolant temp normal

Problems: (as close to WOT in 3rd gear I can get)
Mass Air: Max logged was 40 g/s
CF (all four cylinders): max 11.3 for a good few seconds
Lambda Correction before Cat: 25%

The most telling log (I think?):

RPM ; Specif. charge press. ; Actual charge value
1200980980
1240980980
1320980980
220011601140
312010901220
392011201220
45609801280
41609801130
288013501210
328013501270
356013801270
392013801260
408011601260
43209801240
41209801150

260014801220
260013001240
252013901230
248013801270
252013801250
248013701280
248013801280
260013801280
276013801280
292013501280
304013001270
312013201260
324013901270
340014201290
360014301280
372014601290
392014501290
404014401290
420013501270



Now so far, I have searched and I know I probably have either one of two things - a bad MAF or a vac leak. The only thing I don't get is why it is intermittent, why can I get full, unbridled power sometimes and then limp along the next second? Is this indicative of a vac leak or a MAF on the fritz, maybe a bad N75? this is the main question I'm hoping you guys can help me with, I really want to get this fixed soon. I have also read to try removing the MAF and driving around like that, problem is the problem only happens close to WOT, I dont think it would be a good idea to test this way.

Sorry its so long, i can post the full logs but they don't say much, just that everything is messed up when I try to hit boost.

 

Sorry, I should also mention I'm running bone stock Manual, 1.8T, ATW engine

 

It could be your coils failing. how many miles do you have on the car?

 

 

All of them at the same time and intermitently? I really don't think its the coils... I have a lot of miles, it could be anything due to wear and tear at this point but I can't just go changing everything out.

 

Maybe a DV gone bad if its truely a boost problem not an engine issue. You have a boost gauge 2 check the pressure?

 

ICM is probably bad

 

ATW engine is a 2000 right?No ICM for that year, ignition is controlled by the ECU. also the coilpacks don't go bad often on these cars. I have the original coilpacks at 156K miles.
check for vacuum and boost leaks everywhere, intercooler leak,cracks in hoses...and check/replace/gapyour spark plugs - might be the reason for misfires..

 

Make sure you're using the correct heat range spark plugs.
NGK PFR6Q

7 heat range might run poorly in stop and go.

 

Thanks guys. Did some more logging, my MAF is definately dead. I went to clean it and found that one of the idiots who had the car before me broke the connector so on top of being dead, the connection is probably bad. I'm going to take it in under waranty - i really hate to but I'd rather not shell out money for a MAF and harness.... this should be fun. I was planning on doing oil, tranny, diff, fuel filter, etc etc this week too... damn.