2015, 78K. 2J Intake, NGK -1's, Stratified 91 tune.
Car has been fantastic with no issues. A few days ago, I was driving up the 5 to LA when I got stuck behind a slow car. Dropped a gear to 5th and accelerated to pass and under throttle the car stuttered. I immediately backed off. AP showed that timing was pulled from cylinder 3 but nothing from 4 (the two that I monitor). I wasn't accelerating very hard but I don't remember boost psi or engine rpm. I was not WOT, probably ~50% and probably around 3K rpm. After letting off, the car drove fine to my destination but I kept it out of boost the whole time.
Drove it back to SD later and it was fine but I drove slowly.
Last night, I was getting onto the freeway and in 2nd or 3rd, while accelerating a little harder, it did it again. Sounded like it backfired a little. No timing corrections this time on 3 or 4.
No CEL. Car idles perfectly and starts right up with no problems and no extra cranking. Drives normally too except for these two instances where it seems to miss under harder acceleration.
I ran a datalog this morning on the way to work but I don't expect to see anything. I kept it under 5lbs of boost pretty much the whole trip and the car was completely normal.
No leaking fluids or anything that I can see.
Does this sound like a failing coil? Plug issue? My NGK's are probably just over a year old. I haven't had a chance to take them out yet for inspection but I'll most likely do that tonight. Any other thoughts?
Car has been fantastic with no issues. A few days ago, I was driving up the 5 to LA when I got stuck behind a slow car. Dropped a gear to 5th and accelerated to pass and under throttle the car stuttered. I immediately backed off. AP showed that timing was pulled from cylinder 3 but nothing from 4 (the two that I monitor). I wasn't accelerating very hard but I don't remember boost psi or engine rpm. I was not WOT, probably ~50% and probably around 3K rpm. After letting off, the car drove fine to my destination but I kept it out of boost the whole time.
Drove it back to SD later and it was fine but I drove slowly.
Last night, I was getting onto the freeway and in 2nd or 3rd, while accelerating a little harder, it did it again. Sounded like it backfired a little. No timing corrections this time on 3 or 4.
No CEL. Car idles perfectly and starts right up with no problems and no extra cranking. Drives normally too except for these two instances where it seems to miss under harder acceleration.
I ran a datalog this morning on the way to work but I don't expect to see anything. I kept it under 5lbs of boost pretty much the whole trip and the car was completely normal.
No leaking fluids or anything that I can see.
Does this sound like a failing coil? Plug issue? My NGK's are probably just over a year old. I haven't had a chance to take them out yet for inspection but I'll most likely do that tonight. Any other thoughts?
