so i have a 92 f150 302 and it idle high i was told the iac was bad cause it wasnt plugged in so i got a new one and it did the same thing as the old on witch is randomly rev to 3000rpms and sit there any ideas what else it could be cause everytime i stop i idle at 1200 rpms

 

Anyone?

 

With the IAC unplugged, set the base idle screw to 400-500 RPM or so the engine barely idles, then plug in the IAC and report back.

 

try unhooking the battery for about 15 min first so it resets the computer.

 

Well the idle screw is all the way out and ill try unplugging the battery

 

Any time you do something with a sensor you need to disconnect the battery before messing with it and reconnect the battery after you're done. It could also be your TPS.

 

I bought it like that so i don't know anything that's been done I've only had it a month so im trying to work the bugs out of it

 

Where would the tps be at i haven't seen one

 

Ok so i dis connected the battery it still won't idle under 1000 and now when you let off the gas it will rev to 2 grand and slowly rev back down this is all with the iac plugged in and theidle screw is all the way out

 

What else could be bad