I'm still getting code 42 & 43 under hard acceleration. This happens at the same time as i hear a ticking noise from the engine bay that speeds up with the rpm of the engine. I start hearing the ticking around 3500 rpm, however it doesn't start at the exact same rpm every time.

It is not the rockers too loose as i have tightened them with no impovment. BTW the engine was just reinstalled about a month ago after the rebuild and i have been having the problem since.

87' L98, ZZ4 cam.

Thanks JP

ttt

I was having this same problem. I thought maybe a bad lifter or exhaust leak. It turned out that my timing was WAAAAY off. I fixed the timing and the ticking went away.

I'm pretty sure its not timing. I've been playing with it for a while now, had it from 0-12* with no difference. Do think maybe the ZZ4 cam wants more timing? I would think 10*, where i have it now, should be plenty.

Pardon me for asking the obvious, but I just don't know the extent of your knowledge....

Are you sure its not pinging? I had the same thing, code 43 and pinging under hard acceleration. If thats it you definitely do not want to give it MORE advance, and try higher octane fuel with less timing.

You may have ruled that out immediately, though - just want to make sure. I'm here to help!

Yeah, thanks for bring it up. But it better not be knocking. And it doesn't sound like knocking/pinging.
9.7 to 1 compresssion, 93 octane fuel.

Pretty low compression, plus it didn't go away at 0* timing.
Thanks
JP

Yeah probably not pinging then.

btw, how much timing advance does the ZZ4 like?

Come on guys, i'm about "this" close to taking the car to someone else, cause i just can't solve this problem.
JP

I'd tell you, but I really dont know. Have you tried just tinkering with it to figure it out?

what do codes 42 and 43 represent?

42. Fault at electronic spark timing circuit OR
Fault at direct ignition system OR
Fault at fuel cutoff relay circuit
43. Low voltage at electronic spark timing circuit