What sensors or conditions make the ECU increase the timing?

[emiliog2276]

My Z at the moment runs rough at the moment when i set the ignition timing to 15 degrees. Even though the ignition timing is at 15 the ecu sets the timing at 20 degrees. I do understand these are different things but from what ive read by keeping my ignition timing at 15 im in a way retarding my timing by not making it match the ecu's. This is quite evident because if i change my ignition timing to 20 the cars runs great. I just dont want to keep my ignition timing set at 20 because ive read that it could damage the engine so at the moment im leaving it at 15 and dealing with the hesitation.

My question is what is making the ECU increase the timing to 20?

I know a faulty sensor can cause this. Ive crossed out the tps and coolant sensor since disconnecting them increases the ecu timing to 25 degrees. No codes coming from ECU. Any suggestions even guesses would be appreciated im at a dead end at the moment. Thanks.

[t.mcginley.jr]

If you have already ruled out the coolant temp sensor, then it could be the CAS itself not reading correctly or you're just getting a bad signal when checking it with a timing light? Which wire did you put the pickup on?

[emiliog2276]

If you have already ruled out the coolant temp sensor, then it could be the CAS itself not reading correctly or you're just getting a bad signal when checking it with a timing light? Which wire did you put the pickup on?

CAS was already swapped with another one. Ignition timing was set using spark plug wire extension on cylinder 1. But that not the issue (ignition timing) the issue is getting the ECU to have the timing at 15 since it doesnt matter if my ignition timing is set at 5 or 30 the ecu keeps the timing locked at 20.