Timing Issue

[brian617]

TPS @ .9 volts is high. Watch for spikes in voltage with closed throttle, and do sweep test. Try to get it back around .50-.65 with IAC counts in the neighborhood of 15 hot idle no load.

108 is pulling quite a bit of fuel, monitor ECT for spikes also. ECT defaults to -140* when unplugged, look for that on graphing data.

Aftermarket chips and sockets have the tendency to lose good connection and cause limp issues. Sometimes just re-seating the socket and chip helps with a key cycle.

[srgould41]

I am so upset. I found the issue with the RPM/IAC. Wiring.

Firs, a big thanks to all who added comments! I appreciate everyone's desire to help. I really do.

Backing up, a recent trip through the mountains led to several check engine lights and the computer going into limp home mode. The light and codes reset after a restart so I had no way to troubleshoot. My junkyard wire harness didn't have an ALDL so I installed an aftermarket one, but only hooked up the data and ground wire. I decided to plug the diagnostic wire into the ALDL connector too in case I had the opportunity to check the codes. This had all occurred within a few calendar days and only the next actual driving day.

Last Friday was the first day to start the engine since my last drive with issues and since adding the diagnostic wire. I plugged in my laptop and went for a drive when the issues began. I assumed it was a worsening of what ever tripped the computer the previous weekend. Since last Friday I have not run the engine without the laptop connected. This morning I swapped the ICM (and broke a connector hold down tab) and started it, without the laptop, and it ran perfect. I was happy thinking it was fixed. I connected the laptop and started it up again only to have issues. I had that "ah hah" moment and pulled the test cable. Ran fine. I removed the diagnostic wire from the connector and tried again. Normal. All that work! Gah! I'll put the new ICM back in the dizzy and get back to work on recording a good datalog.

As for the 60+ degree timing numbers I bet it's due to the $61 mask issues. I'll swap to the $42 and try again.