I have a 1994 F150 with dual tanks 4x4 5.0 and I cleaned the IAC valve due to other issues going on which that helped 100% but now my truck is idling at 1500 rpms. I haven't really run it much so could it be that my computer needs to reset itself? Maybe I should unplug iac? I also heard something about too much air getting in the holes in the tps on the butterflys? Should I take off the tps and clean it? Any help would be great.

 

Try resetting the computer, You won't hurt anything cleaning the TPS.

 

It is stuck open try again

 

Stuck open or you lost/damaged the gasket between the IAC valve and throttle body. Or otherwise have a vacuum leak somewhere (did you disconnect any vacuum lines?)

 

Might be the spacer plate between the IAC and throttle body. I have a 1990 5.0 F150 and changed the IAC and had high Idle, it was 2000 - 1500 because the spacer plate was put on backwards, on the 5.0 the plate has holes on one edge, and the holes should face forward on mine, so that the side holes feed the large incoming port to the IAC and not the small out going IAC port on the TB. You might check yours or try it the other way, incase its flipped.