Hi all,
I am fairly new to the board and would like to say thanks for all the posts, the information is great. I am working on my 1988 Camaro Z-28 IROC-Z. The car has been a overwhelming war from the start, but is almost complete. I was having trouble codes 24 and 33 but they have both been resolved. The only problem I am having now is no codes, but the car at slight throttle breaks up and sometimes backfires very loud through the exhaust. The timing has been set at 8* after TDC with bypass disconnected, the TPS sensor is set at .54 volts car not running closed throttle, the knock sensor is new, the ESC sensor is new, the injectors are new, the spark plugs, wires, cap, rotor, distrbutor are also new. This is a 350 TPI. The engine only has about 200 miles on it since rebuild. I was thinking I should maybe check the valve adjustment?? Any suggestions greatly appreciated.

 

Welcome Aboard!

Afterfire (popping in the exhaust) can be caused by excessive fuel/rich mixture, poorly seating exhaust valves weak ignition, incorrect valve timing, and probably a few other things I'm overlooking.

Checking the valve lash certainly cannot hurt anything. If your nose is detecting a rich exhaust, you may want to check the injectors and FPR for leakage, test fuel pressure, and make sure the oxygen sensor is active.