I have a 1985 Pontiac Trans AM. I've replaced a bunch of parts prior to this post. Im in the stages of getting the knick knacks out. I curbed my car after some black ice.

Im trying to time the car at *6 with the computer advance disconnected wire. but after its timed, it jumps back to *10-12* for 5 seconds then back on the money *6.

I think its the Knock sensor being that after I hit the curb hard, the whole engine shut down. I started it up and it had a slugglish performance almost like a MAF was out. but its not. I've replaced the knock sensor before the incedent, but maybe I over torqued it? Im wondering if the knock sensor is even supposed to work without computer, but then again it is fuel injected TPI, my wondering if the cam is walking. i've replaced a lot, double checked the distrubtor timing and found TDC. I checked the idle control valve, replaced it in march Im going to also try dumping the gas out and put fresh 91 maybe even restore my old tank. its cost 23 bucks. just pour the chemical agent in, flush, and then add the tank sealan, shake like hell and dry over night. I also going to check the fuel pressure. Im thinking the pressure regulator maybe be at fault.

Just tell me im a looney

 

You're looney. Once you unplug the timing wire the ECM has no control whatsoever over the ignition advance. Even if it was picking up detonation the ECM couldn't retard the timing any further than the base setting, which is what you get with the timing wire unplugged.

 

When I rev the engine, it backs off from *6 degrees to like *10. you think theres a vacuum leak, or its misfiring. its doesnt sound like its back firing but there is hesitation on the throttle.

 

with Ecm disconnected from timing?


Loose timing chain?

 

Yeah with the timing tan wire disconnected. It *10 degrees or 12ish. I was told it could be the timing chain loose. I disconnected the knock, but it still jumps. Imagine looking at the balancer at *6 then it jumps back to 11* then four seconds later its back at *6. I connected the tan wire back and it idles at 1000 rpms. Maybe a vac line,? but the timing chain. do i got to take the oil pan off? i hope not.