5k rpm and up stutter with log, please help.

[supravw]

I have looked at other threads with the same description but none of the info helped.

I have a 92 Tsi that is at stock boost (bcs still connected), basic mods are 3" exhaust turboback, 16g turbo, autometer boost gauge and that is it. I've been having a problem with stuttering/breakingup at 5k, 5.5k, 6k and up. I have replaced the plugs, wires, fuel filter, mas, intercooler and piping, rebuilt the TB and replaced vaccum lines with no change. I just got a logger finally and took a log today. I can't really upload the log but I'll post all the info.

At idle (800-1000rpm)-
KNCK-0
O2- .03 (cycles)
TPS- 8.9%
TIMA- ranges from 10-16*
COOL- 182.7*
AIRT- 41.1*
BATT- 14.2

At 3718 rpm- WOT pull
KNCK- 1
O2- .91
TPS- 56.2
TIMA- 18*

At 5125 rpm-
KNCK- 0
O2- .93
TPS- 96.4
TIMA- 19*

At 5531 rpm-
KNCK- 7
O2- .91
TPS- 96.4
TIMA- 22*

At 5625 rpm-
KNCK- 21
o2- .82
TPS- 96.4
TIMA- 20*

At 6187 rpm
KNCK- 21
O2- .13 << ????
TPS- 96.4
TIMA- 21*

At 6500 rpm
KNCK- 21
O2- .07 << ????
TPS- 96.4
TIMA- 22*

Any ideas on why my O2 voltage like that? I'm not sure how to read logs yet, but the timing seems to be ok, and it doesn't knock untill the first stutter and the 1 count at 3700.

Any ideas and help would be great thanks!

 

[GSX93DSM]

21 counts of knock is too high for one. Also what fuel mods you have.

 

[supravw]

21 counts of knock is too high for one. Also what fuel mods you have.

I realize it's knocking a lot, I need to know why. I have the mods I listed, it's basically stock with a 3inch exhaust and 16g turbo on stock boost.

 

[Defiant]

The first suspect in a 5K miss is spark plug wires. Second is plugs.

 

[99GSTEvo3]

Same issue, not nearly as simple as plugs.wires, built a lot of dsms and this has got me stumped, mine hits a hard wall like fuel cut at 4500-5k, car runs super rich 10- 10.5 on wideband starts hitting full boost and creeps to super lean at 4500ish and bam loud pops brick wall etc. Now for the list of things ive repaired or swapped parts, plugs .028, wires, coilpacks, transistor, maf tps, injectors, ecus, cam sensor, o2 sensor, injector resistor box, fuel pumps, fpr, turbos, 70mm back to big 16g, Boost leak tested rebuilt throttle body replaced seals, holds 30psi for a good minute. As for mods, all of which were done after the problem which i bought the car with, 510cc injectors, 255 walboro, front mount, hard pipes, big 16g, greddy rs bov(swapped several out and revented to intake didnt matter)open dump, hks intake, hks tb elbow, no balance shafts, 3in turbo back, btw 92awd6bolt4bolt. Any help at all on this, sounds similar problem to posters problem, its got me and my dsm friends completely stumped, theres nothing we havent swapped out on this car, ive been testing sensors and tracing harness wires but so far nothing bad yet, begging that someone has seen this no dumb responses please ive adjusted/replaced everything possible on this car except for the physical long block, btw cam timing is dead on. Let me know guys Thanks.

 

[supravw]

The first suspect in a 5K miss is spark plug wires. Second is plugs.

Both have been changed.

 

[Defiant]

Ngk Bpr6es, .0028" ?

 

[Colt4G63 also]

Are you running DSMLink? If so, do you have "Use fake MAF" checked, and your switchover set to 2000Hz? I had the same problem and it turned out to be MAF over-run.

Ps. Great avatar. Reminds me of something... Oh yeah, my engine:

You must be logged in to view this image or video.

 

[nytescion]

I'm having the same issue I'm going to try getting a new coil. or possibly a COP setup. I did a test (some kind of oscilating test of ignition system) at the shop a couple of days ago and results suggested that my coil is quiting. This is the only thing I haven't changed also.

 

[motomattxxx]

Same issue, not nearly as simple as plugs.wires, built a lot of dsms and this has got me stumped, mine hits a hard wall like fuel cut at 4500-5k, car runs super rich 10- 10.5 on wideband starts hitting full boost and creeps to super lean at 4500ish and bam loud pops brick wall etc. Now for the list of things ive repaired or swapped parts, plugs .028, wires, coilpacks, transistor, maf tps, injectors, ecus, cam sensor, o2 sensor, injector resistor box, fuel pumps, fpr, turbos, 70mm back to big 16g, Boost leak tested rebuilt throttle body replaced seals, holds 30psi for a good minute. As for mods, all of which were done after the problem which i bought the car with, 510cc injectors, 255 walboro, front mount, hard pipes, big 16g, greddy rs bov(swapped several out and revented to intake didnt matter)open dump, hks intake, hks tb elbow, no balance shafts, 3in turbo back, btw 92awd6bolt4bolt. Any help at all on this, sounds similar problem to posters problem, its got me and my dsm friends completely stumped, theres nothing we havent swapped out on this car, ive been testing sensors and tracing harness wires but so far nothing bad yet, begging that someone has seen this no dumb responses please ive adjusted/replaced everything possible on this car except for the physical long block, btw cam timing is dead on. Let me know guys Thanks.

In your case it sounds like fuel cut, with only 510cc squirters you aren't pulling much airflow from the maf signal, the 16g can flow enough to put you at fuel cut easily on a stock fuel table.