Hello,
I have a 1994 Ford E-150 5.8 V8 EFI and it has a high idle almost like a rocket or plane running and it does it from start up and won’t stop I talked to some older mechanics that know more than I do and they didn’t know anything about it and wanted to argue that in 1994 they didn’t put that engine in the vans so they wouldn’t help either because of that so it I replaced the throttle body gasket, throttle position sensor, Idle air control valve and cleaned the throttle body thoroughly and it still hasn’t fixed it I have checked for vacuum leaks also and another mechanic showed me how to test the PCM to see if it was bad and it wasn’t so at this point I’m stuck as to what the issue could be and it was dealership mechanics that I know and asked and they didn’t know either. I bought a Ford OBD 1 scan Tool but it doesn’t have a check engine light so I can’t use it for this issue could something be wrong with the ECM possibly or is the throttle body itself bad? I don’t want to keep throwing parts on it if it’s not any of those. It has been sitting for about a year but has been started and it just started doing it a few months ago so I don’t know if that would be something to do with it or not.

 

Sorry just realized I posted this to the wrong thread