High Idle during Startup

My 2000 Winnie LX 3.8L revs up to 2000 rpms for about 5-10 seconds @ start up. Also, when the accelerator pedal is depressed, it will not return back down to idle until 5-10 seconds later, even if the pedal is immediately released. When the a/c compressor kicks on, the idle bumps up, as it should, however won't drop to 1100 rpms (stays up @ 1500) for a long while. These things happens at all temperatures; 1st thing in the morning, to after fighting traffic for hours.

I've cleaned old IAC solenoid, no help. I've replaced the IAC today, no help. I checked throttle cable, cruise control cable, all good. No trouble codes displayed. I did disconnect the IAC wire, it would idle @ 750 rpms, steady! During start ups, depressed gas pedal - idle returned immediately to 750 rpms. Only thing, as soon as I put it in gear, it would die out. Needs the IAC.

It seems as though the IAC is being commanded to stay open excessively. Any and all help/suggestions is greatly appreciated.

It sounds to me like you have a small vacuum leak somewhere that is sneaking air into the engine and adding to the IAC flow. With the IAC plug wire removed, the engine should die immediately after starting. Since yours runs w/o the IAC even hooked up, there has to be air getting in, at least that seems logical. GLTY, check over all vacuum hoses carefully.

Thanks BDAHL, vacuum leak; sound advice. I'm going out to the van right now to chk it out. BTW FYI IAC $201. WT?

Thanks again BDAHL! After looking around, found vacuum hose came off. (located between fuel injector rails (3/16" hose) and throttle body (1/2" hose) - U shaped hose that supplies vacuum for some sort of shiney metal diaphram situated between the two fuel rails above valve cover) Seemed like oil coming out of the throttle body 1/2" nipple which allowed the hose to work it's way off. Also, had to lock wire hose on since now it's (hose inside diameter) is too large. Winnie is good as new.:tongue:

Always like to hear back when the problem gets solved. Too bad you're out the $201 on that new IAC valve.

In the future, if you have the time to wait on parts, you may want to look at these online vendors. IAC for OEM part was about 100 bucks + shipping so might have saved some big green.

https://www.rockauto.com/dbphp/mak,FORD

http://www.trademotion.com/partlocator/index.cfm?siteid=213787