Hey Guys,

I have a problem with my 95LT1 Camaro that is driving me crazy. I drove to the track a few days ago and it drove fine. The first pass I made was good, second was great, after the third pass it backfired through the intake on the return road. The next time I tried to make a pass the car bogged all the way down the track. Now if I sit in the driveway at idle and hit the gas I get a backfire through the intake. I've attached a picture of TunerCat at the exact time it backfired. My knocks are way out of line so it's retarding the timing. I checked fuel pressure and it was at 43PSI when this happened. I am running 93 shell fuel. Please help!

Thank you,

 

You indicated it backfired while on the return road. The DataMaster screen shot tabular data indicates the throttle was 65.5% open, engine RPM was 875, MPH was 0, MAF was 95.65 g/sec, MAP was basically matching the barometer (101.1 kPa) . Doesn't seem consistent. You are aware the "Record" shown for the tabular data (#164) does not match the record selected by the graph cursor (#30)? That's normal, just because you put the cursor on the graph where you want it does not cause the same frame of data to appear in the tabular presentation.

A pop through the intake could damage the MAP sensor, MAF sensor, or the throttle body blades, blow off vacuum lines. Did you check those?