2200 rpm idle!!!

[5.0Torx]

hey all, i fired up the beast today and it went to 1100 rpm or so, like usual, and then all of the sudden went to 2200 rpm. still held about 20 inches of vacuum. i shut her down, restarted, and its been acting normal ever since.

why do i get the feeling this is one of those problems thats either going to get worse as time goes on, or cost me $45,000 to fix? whats going on?

 

[90limited]

My guess would be the IAC (Idle air control I think) valve. Sometimes they stick and sometimes they go bad. Part is under $100 and takes 10 minutes to put on.

 

[NIKwoaC]

An annoying/strange whistle at idle sometimes indicates a failing IAC valve. You can take apart the IAC, hose it out with carb & TB cleaner, and put it back together. That sometimes will fix it, and keep it from sticking. If not, you'll have to buy a new one.

 

[5.0Torx]

actually, come to think of it, i do hear a whistle at startup but i figured it was my lack of an air silencer.

also, would a bad IAC stop it from fast idling (1300) in the winter? ive noticed that itll go to 1100-1300 now thats its moving into fall, but when its butt ass cold outside, it is hard to start and idles at 800.

 

[bentley429]

When its running at the 2200 idle, unplug the IAC if the rpms drop to normal thats the problem. May be able to just clean it, Ive never had luck with that though.

 

[HISSIN50]

When its running at the 2200 idle, unplug the IAC if the rpms drop to normal thats the problem. May be able to just clean it, Ive never had luck with that though.

Sound advice here, on both counts.

I don't recommend cleaning an IAC unless someone is already prepared to buy a new one. The attempt to clean them can do more harm than good.

 

[jrichker]

See the "Surging Idle Checklist for help with all your idle/stall problems. The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.