Racerx974

Ok guys new to the forum and need some help. Have an 89 iroc 5.7 tpi that makes popping or backfire sound sometimes on acceleration from stop sign or if I give it a lil gas after at one speed for awhile. If I hammer it after it does it, I can run tach to 5500 and takes off like a banshee with no missing hesitation. I've changed plugs wires cap rotor, cleaned maf sensor, intake temp switch. Car isn't running hot, started doing this when it got warm out. If it's weak fuel pump I shouldn't be able to run her hard without it puking on me right. One time it did it I smelled gas. Could it be purge valve/solenoid on charcoal canister? Plus it's not showing any codes/ no lights on. I did have to do an ignition bypass on car because ignition lock for vats crapped out but mechanic did that with a kit he bought, wasn't cobbled . Outta ideas

tyeo098

Did you check timing?

danryanm

Vacuum leak?

Racerx974

Was gonna check it this weekend, wondered if it could b just tick off and cause condition.

mmadden55

Timing I think.

mantaguy

iTrader: (5)

Most likely timing when it backfires through the carb

Racerx974

I thought about timing but if it's a timing issue it should do it all the time shouldn't it ? Going to check to see if there's any codes on it this afternoon I will still check timing though thanks again

Racerx974

Not timing and no codes. Wtf!!😡Aggravated , guess I'll check for vacuum leak maybe?