I had this on the TPI board but no one had any answers, so i thought i would give the electronics board a try.

Ok I have a 92 TPI Camaro with a 355 and mild cam. The engine had been running fine but i started to notice the engine starting to knock under a load. I traced it down to the timing. The timing never advances and is out of the timing marker on the retarded side when it is running, and out of site when you put the engine under a load. Its kinda like its doing the opposite of what it should be doing. I have tried a new ecm, new prom, new dist. module, new knock sensor, and cannot under stand whats making it retard the timing so much. If i unplug the timing advance wire and run base timing its fine, no knock and its rock steady on 6 degrees. I'm at a loss i'm not sure where else to go. The only other thing that i should mention is the car was a 6 cylinder and i re wired it for the v8. I have double checking the wiring but i doubt the problem is there since this problem has just showed up and it worked fine before. Any direction would be great. Thanks in advance, Brad

 

Your positive it wasn't dis-advancing the timing before?

 

Have you checked the harmonic balancer? They are known to slip sometimes and give incorrect timing readings.

Lou

 

I will check the balancer tonight and see if that may have slip. Thanks for the input, i'll let you guys know how it turns out.

 

The balancer is fine it has not slipped. Any other ideas?