My dad has a 90 Formula with a 350 ZZ4 Crate motor with SLP runners, lingenfelter intake, edelbrock headers, and a Flowmaster catback. Lately when the engine is warm it has begun to ping, miss, and sometimes backfire under light acceleration.

To date I have checked the timing (6 degrees), changes plugs, then changed the gap from 35/1000s to 45/1000s. Then I replaced the EGR valve and finally disconnected it. Nothing seems to help. Any ideas?

 

Maybe a faulty or bad Knock sensor??? Maybe some bad gas? What octane is he using? I would only use 93+ for any V8........

 

yeah, i was about to say i hope your using 92/93 octane if you start to hear pinging. set your timing at 8* and see if that helps some. whats your fp set at?

 

-------------Sorry for the misinformation, but the timing was set a 6 degrees before and after their were problems.

I was told that the mechanic did a compression test and it was fine. I can get the actual numbers soon.

My dad is going to pick up some octane booster tomorrow.


It's not the gas, because we have filled up with different gas, and still have the same problem.

I'll have the mechanic find out what the fp is at soon.

 

The problem turned out to be the distributor shaft. The magnets were not working properly I believe.

 

I hate it when those darn magnets decide to act up!