Idle problems

[Racing_Rush]

Ok I have a very unusual problem I can turn the car on when its cool and everything runs fine with the idle nice and steady, I drive it for 30 minutes... Then I turn the car off leave it for 20 minutes come back turn the car on and in park the idle will bounce from 1000-500.  Put it inot reverse and it will shut off....

I had a problem with one of my coils which i replaced, that gave me the power i have been missing for over a year and my fuel economy back, so I replaced all 3 with MSD units, I checked the IAC which had a thin oilly resedue on it? ÂÂÂ I replaced TPS sensor with a used one with no change... Put in new spark plugs... No check engine light... ÂÂÂ Fuel filter was replaced a year ago...  I replaced the ICM with a used unit with no change...  Also it *was* stumbling when i hit the gas hard.  Problem went away when i changed coils i think...

It runs perfect! Till you turn it off!

[rweatherford]

Try cleaning the TB and IAC motor and air passages.

It doesn't cost much and cannot hurt anything.

[Racing_Rush]

When I looked at the IAC and noticed the gunk I pulled off that thing on top and had a look inside its not clean but not obstructing anything.  

I reuse all my gaskets could this be the problem?  They are getting pretty old... My EGR gasket especially... I also never replaced the O-ring on my IAC...

I am going to be checking my PVC pipe and seeing if its connected probley and probley relocating my pvc valve to the front valve cover.

[rweatherford]

I usually also clean all the passages of the IAC and the seating surface.  Did you also clean all of the TB area?  Wipe off the edges of the TB and TB plate.