I have a 1999 with 132k on the chassis that I put the engine from an '02 with 52k miles and a turbo into. I'm currently facing an issue with backfires and sync loss around 3000 RPM, in gear and while just revving. So far I've replaced the Cam Position Sensor, replaced and checked the sparkplugs (.030") to no avail. The ignition and harness are from the original '99 motor, so I'm doubtful they're to suspect (however my tuner says he believes it may be the harness). The car also has FlowForce 640cc injectors. Attached is a log, showing a few of these events (640s, 648s, 668s, 678s ,697s etc.) Does anyone have any advice or ideas?

 

Accidentally uploaded the wrong log for the driving one. Post has been updated with the correct one. Also, I managed to get the car to rev to 6k+ in neutral a moment ago, but it still refused to go above ~3k while actually driving.

 

85 lost sync counts in the 2mb log file. Have you tried adjusting your pots?

 

It is a MSPNP-Pro, I don't think the pots are adjustable on it.

 

Might want to try adding a capacitor on the coils. I think the earlier and the later ones run a capacitor included in the harness for the coils whereas the 99-00 didnt have one. At least my 99 harness didn't have one. I added one and it cleaned up the rpm signal a bit.

 

I'll look into this further, seems like it may be worthwhile.


Attached is a composite log showing the sync loss. I can't seem to find any glaring issues that may be the cause.


(screenshotted part of the composite).

 

Trigger wheel had a damaged tooth and was slightly warped. Solved thanks to Matt from DIYAutoTune