honeybadger
Just don't care
- Thread starter
- #1
Hi all,
Bit blown away - am feeling this is all related to the AC repair fiasco (where the engine harness was pinched), but want to do my due diligence and diagnose as best as possible. Eliminate all other options!
Context - on Saturday the car was giving me a random misfire code (P0300) while out at MSR-Cresson. We ran the codes at the local performance shop, Dog House Performance, and the car showed all parameters as good (fuel pressure, ignition coils, etc.) - just the misfire (and no particular cylinder). Misfires only happened at full throttle. Our best guess was bad plugs or bad gas because it only seemed to misfire when the car was advancing the timing. So, it was obviously detonation-related. I put new plugs and filled up with some VP100 fuel to clear things out. Car worked great for the 1 remaining session I made it into - about 45 mins of straight track time. No problems.
Then yesterday I ran it for about 3 hours of track time again with no problems. On my final 2 laps of my second to last session, it started acting like it had fuel starvation (power cuts, no check engine light). I come in, check things out - have fuel, no disconnected vacuum lines, etc. Go back out for final session and it freaked out as soon as I hit the track. CEL came on. Roll over to Dog House again and we read 2 codes:
p144A - Evaporative Emission System Purge Vapor Line Restricted/Blocked
P0193 - Fuel Rail Pressure Sensor Circuit High Input
Current hypothesis is that the vapor line restriction is causing the high pressure in the fuel rail since it can't evacuate. Thoughts?
Given that this car has had a few problems with electrical connections since the AC repair fiasco, I am wondering if it's related. The most common fix for P144A seems to be replacing the purge valve, but I would like to trace the circuit and make sure the connection from the PCM is intact. Can anyone provide a schematic for that?
Thanks for the help!
Bit blown away - am feeling this is all related to the AC repair fiasco (where the engine harness was pinched), but want to do my due diligence and diagnose as best as possible. Eliminate all other options!
Context - on Saturday the car was giving me a random misfire code (P0300) while out at MSR-Cresson. We ran the codes at the local performance shop, Dog House Performance, and the car showed all parameters as good (fuel pressure, ignition coils, etc.) - just the misfire (and no particular cylinder). Misfires only happened at full throttle. Our best guess was bad plugs or bad gas because it only seemed to misfire when the car was advancing the timing. So, it was obviously detonation-related. I put new plugs and filled up with some VP100 fuel to clear things out. Car worked great for the 1 remaining session I made it into - about 45 mins of straight track time. No problems.
Then yesterday I ran it for about 3 hours of track time again with no problems. On my final 2 laps of my second to last session, it started acting like it had fuel starvation (power cuts, no check engine light). I come in, check things out - have fuel, no disconnected vacuum lines, etc. Go back out for final session and it freaked out as soon as I hit the track. CEL came on. Roll over to Dog House again and we read 2 codes:
p144A - Evaporative Emission System Purge Vapor Line Restricted/Blocked
P0193 - Fuel Rail Pressure Sensor Circuit High Input
Current hypothesis is that the vapor line restriction is causing the high pressure in the fuel rail since it can't evacuate. Thoughts?
Given that this car has had a few problems with electrical connections since the AC repair fiasco, I am wondering if it's related. The most common fix for P144A seems to be replacing the purge valve, but I would like to trace the circuit and make sure the connection from the PCM is intact. Can anyone provide a schematic for that?
Thanks for the help!
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