I'm Stumped!
'87 Chevy G20 van 350/TH700
I have NO codes and it STILL idles 1200,1400, or higher. No vacuum leaks, Temp switch(for computer) is new, no help at all! I took a look while running and noticed that the nearly new IAC solenoid is wide open, so I swapped it out for one from another TB unit that I know was good...Bout 900 at start, held for a few seconds, and slowly pulled beck and the RPM's started to climb...same problem...
What is causing my IAC to go full open and NOT give any codes?
I am gonna go get an O2 sensor and install it in the parking lot...its about the only thing that I don't have a spare of!