Engine idle

I have a 1992 Ford Taurus with a 1993 3.0 engine in it. The motor will rev up and down at idle. Problem seems to be when you first start it and usually goes away when it warms up, but sometimes it doesn't. Any ideas ?

I THINK YOU NEED TO REPLACE THE IDLE AIR BYPASS VALVE AND AT THE SAME TIME , CLEAN THE THROTTLE PLATE .

I just replaced my IAC (bought from Rockauto.com) and cleaned the throttle body and intake with some "throttle/intake cleaner" STP type from Autozone. It runs smoooooooth now!!

Joe

I have this same problem with my 97 taurus 3.0 Vulcan could u please tell me where to locate the Idle Air bypass valve so that i can change that in my vehicle! thanks

If your looking at your engine, the IAC would be setting on backside of the throttle body, closest to the cowl. And its held on by two screws. It's shaped kinda like an "L". It has a connector with I believe two wires going to it. Hope this helps.

thanks im currently trying out some throttle cleaner STP type fluid and will attempt to have that changed if this doesnt resolve the problem

Just a maybe kinda thing. you may have a vacume leak to check it I usually use some carb cleaner and spray around the intake plenum, manifold, throttle, valve covers and some other places i cant think of it will change the engine rpm instanly when u find the leak egr too. Fuel pressure regulator can aslo do this and the MAF sensor when it is drty can get u a loaping idle.

When I first start my 98 taurus it is fine, when I put it in drive it will gear down so low it seams like it will die, then I hit the gas and we go. coming to a light or stop it does the same thing. sitting still in park or nuetral it will go up and down, sometime so low it will die. I just got it back from the shop and he replaced a hose at the bottom of my radiator that he said was leaking onto my belt that runs the motor causing it to slip. it was still doing it when I picked it up but not stalling all the way yet, just going up and down. from what I have read on here. he was not even close to the problem, so why did it better? .......confused???? Please help, and thank you in advance.

sorry I meant... why did it get better? and he also replaced the belt. can't remember the name of the belt, but it starts with an S.