Engine reving up and down when coming to a stop

Today.. All of a sudden the engine wouldn't idle when stopped.. It would rev
up and down... It was strange.. It happened to me once before and I noticed
it happens when I run the AC... After I turn off the AC and put it in
neutral and stablize the idle.. It will idle fine... Very strange.. The only
thing I can think of is the AC idle control or some relay going bad...
Anyone else with this problem and any ideas how to fix it..

It is a 96 SL2

Thanks,

Ben

 

Maybe the throttle control motor (looks like a black solenoid) plunger
mounted on the side of the throttle body is carboned up. Toothbrush and
throttlebody cleaner are the Rx after pulling the small Torx screws holding
it in come out.

B~

 

At that point, it's best to remove the entire assembly and give it a
good cleaning with throttle body cleaner. Don't use carb cleaner, even
though it's cheaper. Believe it or not, the TB cleaner really is a LOT
better.

The TB comes out with 2 10mm bolts. Don't kill the gasket

Remove the sensors and clean clean clean. I bet it's really dirty in
there.

Once you put it back, give everything a lookover for any cracked,
rotted, or missing vacuum lines - these two can cause grief with varying
idle.

 

Well, dunno if this will help, but I had a similar problem in my 98 SC1 a
few weeks ago. The car would rev high at idle for no reason. Turns out it
was a faulty engine temp. coolant sensor (ECTS), which is an easy repair...I
did it myself for the cost of $20 part. Check out www.saturnfans.com and do
a search for ECTS replacement. The old ECTSs are resin tipped and crack
with time. If you haven't had yours replaced, this may be it. The new ones
are brass tipped.

Hope this may help!