idling way too high at start

[plymouthtalon]

Hey, weather just got cold here in StL, temp. got down to the 20's. Now when I start the car the idle jumps to 2500 rpm and idles there until I drive for about ten minutes. Then it idle surges from about 1k-1500 rpms for a few minutes, and then the idle goes down to 8-900 rpms and is steady. I don't think I have a vacuum leak, vac on the boost gauge is ~14 hG at idle, ~22 at decel. My past DSM's have idled higher when it's warming up, but not up to 2500. Any thoughts?

 

[BOBS90TURBO]

I am going through the same thing, I have been looking into the problem and it sounds like a ISC motor, I am installing a new one in the morn and I will let you know if it is the fix.

 

[FASTSPOOLINGST]

mine does the exact same thing, the guys i work with theirs all do the same too. I believe it is normal in cold weather.

 

[rabi42]

I read somewhere that giving the trottle body a good, thorough cleaning with help fix that. Apparentally carbon and junk plug some of the small passages and cause it to idle too high at start up. Anyone done this?

 

[TSiAWD666]

Idle vac should be 18mmHg at idle, and 25 mmHg on decel. I think you have a leak. I can't however state that it's directly related to your supposed "problem".