I wonder what percentage of the questions here are from me about this car...
When I try to accelerate with more than about 60-75% throttle at lower RPM (say, under 3k or so), the car starts to accelerate, then acts like there's a fuel cut. This will continue until I let off of the pedal. I can accelerate gradually and eventually hit WOT without an issue, but doing it fast always causes this issue unless I'm already at a higher RPM.
I've noticed that, when this happens, my AFR shows a (surprising) 10 - 10.5, which also happens under WOT when the car is running correctly. Way, way rich. When I let off of the throttle, I can smell gas.
Recently, I've replaced the exhaust (cat-back), fixed the downstream O2 sensor that had the wiring harness slashed. I reset the ECU after that. (Note that this problem started a few weeks ago, before I fixed the O2 sensor or replaced the cat back.)
I also have a CEL, with the following DTCs:
P0010 - "A" Camshaft Position Actuator Circuit/Open Bank 1 P0011 - "A" Camshaft Position - Timing Over-Advanced or System Performance Bank 1 P0455 - EVAP System Leak Detected P0507 - Idle Speed High (and it is)
When coming to a stop, the engine frequently revs up to ~2500RPM.After a few seconds it'll go (usually) go down to 750-1000RPM.
The car has an aftermarket turbo, and is tuned for this kit. However, I've had weird issues ever since I put the kit on.
I've checked the air filter and spark plugs. Everything looks fine. I recently replaced the turbo-to-exhaust manifold gasket which had exploded.
Any suggestions? I'm running out of ideas. I'll check the cam sensor and make sure it's properly connected but I doubt that's the issue.
I replaced both cam actuator solenoids and the hesitation is gone, however now the car sounds horrible (somewhat like a Diesel) at idle, though I can hear then noise at lower RPMs while moving, as well.
Vacuum on my boost gauge used to be ~25mmHg at idle, now it's ranging from 15 to 20. Which (to me) also indicates a vacuum leak. Really, really going to try blocking off the EVAP at the throttle body today.
I suspect the 10 AFR readings may be near the limit of the sensor or gauge's useful range. (It's an AutoMeter wideband, upstream from the cat.) I'm going to hook up HPTuners this afternoon and do some logging.
Oh, and I had a very nice backfire on the way to breakfast this morning after letting off the throttle at high boost/RPM. I thought to myself:
"Self, this neighborhood is really going to crap. I mean, who shoots at a stranger before breakfast?"
This morning, the car is running REALLY rough. It tried to die at a stop light a few times. Typically when this happens, it smooths out once I get moving, which it did a few times. However, after the last light I stopped at before reaching my destination, the car started surging pretty badly, almost as if I was hitting the gas like a snare drum.
Before I left this morning I hooked up HP Tuners and captured a log file. If anyone here has the expertise to interpret this in a useful way, please, please speak up.
I did make it for a day and a half without a CEL after replacing the cam actuator solenoids and resetting the computer. Now, I have another DTC (P0171 - Fuel Trim System Lean Bank 1).
This is getting a little long - maybe I should start another thread.