Engine Idle

[Daddude]

I have a 94 Bronco with a 351 that idles high after warm up. Ive had her since 97 and the RPMs are 1200 at start up and then should drop to about 600-800 RPM after 15 to 30 seconds.Now at start up the RPMs stay at 1100 after driving( no matter how many miles I drive) Whats this about any suggestions.First problem Ive had with the engine and it drives fine as before- just this high idle. B)

 

[mustangman65_79]

Three things,

1. Throttle body sticking

2. Bad TPS sensor

3. IAC bad or sticking

 

[Daddude]

The high idle problem was solved today after many attempts.The three things you suggested were tried and the end result was that the Throttle position sensor was bad. I had cleaned the throttle body, bought a new IAC sensor unit and still had the problem.I disconnected the new IAC and she ran at about 600 rpms at idle but you had to hit the throttle a bit when starting up but ran OK until I had the time to mess with it more.Today I spent about $45.00 for a TPS which some said was not the problem for no check engine light was lit up.Well they were wrong and Mustangman65 was right on!! Thanks dude you saved me about $200. or more for what the shops would hit you for.