Hi,

I have a 98 Tahoe 5.7 with a 411 pcm and just got my V1 commercial so I did a relearn and everything is running fine. When I checked the CMP retard(vortec) it read avg -40.75.

I tried to adjust it by moving the dist. one tooth forward and then it read between -80 and -50. Then I tried the reverse direction and was able to get -35, so I moved it back one tooth and tried again and it wouldn't start at all. I ran out of time so I just put it back where I started at -40. It starts fine and doesn't throw a code, so is the scan tool reading incorrectly? Or is it really -40 off and I just need to try again?

Maybe I'm using the wrong PID but I didn't see any others that seemed correct.