Looksthakill

Hey Guys,

Thought I would post a recent experience I had with my 86 5.0 HSR.

After a couple of months of solid running, I started getting intermittent Service Engine Soon lights, and rough running. When I attempted to pull the error codes, I would only get "Code 12." No other error codes.

Long story short, I checked my TPS voltage, and it was LOW. Specifically, .24 volts. I set it to the recommended setting with my voltometer (0.54Volts ), and the car is now running normally.

Not sure how it came out of adjustment, but for the time being, it is running solid.

Thought I would pass my experience along. Check that TPS voltage!

FYI, I followed the procedures noted here: https://www.thirdgen.org/tpimod2

Bronze85

I agree, setting TPS and then IAC makes a world of difference. If out of spec the ecm basically assume the throttle is in a different position and adjusts from that. It should be done after base timing is set.