Eagle Trouble PLEASE HELP

1992 Eagle 2000 GTX
2.0 DOHC
Auto
Car is from the U.S

Problem
The Idle Will Rev at 2500rpm when i start the car then drop to 1000
but then it starts to bounce from 500 to 1500 Seems to be ok these last couple of days it was -10 But when the weather starts to warm up the problem comes back

I was told it was the Idle Air control Motor So i picked one up
$280 later and the problem is still there


Please Help
No one in my area seems to be able to tell me whats wrong
And it's really do \ing a # on the trans

I had the same problem on the 1996 Talon a few years ago: checked the plugs and wires, noticed oil around the number 2 spark plug wire. I think this was causing it to misfire. All it took to correct was to take the top cover off and put new "o" rings on it . I'm no mechanic, and can't recall all the correct names for things, but it ended up being something I was able to do with about $70 dollors in new parts , including the plugs and wires and rubber "o" rings. Check your plug wires, just pull them out if the engine is similar to my "96. If you have oil around them, I would bet that is your problem.

fixed

It seems it was the Idle Air control Motor

I just failed to blow out all the Carbon that was built up