Alright. I am still trying to trace down my code 43 "forced knock" issue. Camaro is an 86 with an 89 engine TPI. For starters I have replaced the esc module with the correct one needed for a 350. I have replaced the ecm with a known good used 165 ecm. The knock sensor does work when using a scan tool. Could the knock sensor still be causing the forced knock issue at WOT?

What could be the cause is that I run 93 octane. I have to with the chip I am running. I have tried 87 but the car sputters and stalls and runs rough. I have not tried 89 octane (I can't imagine dropping from 93 to 89 would make a difference).

The other issue I think could be a culprit is I am fairly certain the memcal is for a 305. Which is piggybacked with a chip for an 87 350. I am looking at getting a custom chip soon but my question is since my cooling fan is directly controlled by the computer don't I have to keep the 305 memcal?

This is all new stuff for me (ecm related issues) so I'd like some input from more knowledgeable people.

 

IIRC, there is an option flag to disable the forced knock test. Or maybe it was a temperature dependent variable. Not all TPI calibrations have it enabled.

Going from 93 to 89 octane is a bugger jump then going from 89 to 87 octane. May be enough to get the test to pass.

RBob.

 

I want to try 89 octane, but I am fairly certain the chip I have now says it requires 91. Is 89 octane close enough? 87 made the car run like crap.