Hi all, new to the forum, but i have a problem.. My 96 f150, 5 liter, 5 speed, 2 wheel drive, is idling high, but only when its moving. Whenever im driving it, itll idle at about 3000 rpm, and ill have to ride the brakes as if the cruise control is on. If i clutch it, itll idle at 3000, and stay there the whole time i coast until i stop. When i stop, it goes back to regular idle, and when i move again, back to 3 grand. Any idea what this could be? Thanks!
Phil

 

Hmmm... How tight is your throttle cable? Maby its too tight? My 1992 idles high until it warms up then it idles normal. My mechanic said its just because its the computer finding the idle speed with the govenor or somthing like that (he didnt say something like that im not exactly shure what he said been a while since i talked to him). Maby your computer needs to be reset (if your able to). Im not for shure i jope i was a help.

 

checking for codes would be a good thing to do. also cleaning your IAC wouldn't hurt either.

 

Mah high idle turned out to be the TPS -- it would race up out of nowhere (I have an automatic) to the point where Id have to slam my foot on the brakes to keep it from moving at a stop light.

Those on this forum swear by the ford ECU and its ability to give useful alarms.

So pull the codes FIRST (if you can).

If you dont/cant do this - I would:

1) check for vaccum leaks (vaccum leaks casue high idle usually about 500 rpms higher)


2) take off your TB and IAC and clean them both til they look new

3) replace the TPS


again, this is if you cant pull codes and have to do it the old fashoned way.

 

thanks for the replies all, but i dont know as much as i should about my f150.. what is an IAC and a TPS? haha thanks again