Aurora runs away while idling.

Here's hoping someone can give me some insight on this. I have a 2001 Aurora, bought used with 50,000 miles on it. Shortly after I got it, it started to idle up at odd times, even while driving it. Sometimes as high as 3000 rpm. I have had it at a dealer 3 times for this and they are unable to daignose the problem. The only way I have found to get it to idle normally is to shut it off and wait a few seconds, restart and hope for the best. Sometimes as many as 3 times to get it to idle normally. Check engine light came on and the dealer diagnosed this as a bad throttle position sensor but so far (3 weeks) I have been unable to get one delivered to the dealer for replacement. Also have a light flickering problem. Alternator voltage flucturates, lights flicker, (dash and headlights). A new alternator, if you can find one, is about $300.00 plus labor. Any assistance would be greatly appreciated as the dealer is stumped on the idling problem and I am really against paying that amount for a new alternator.
Thanks

what i would do is check and clean for any loose wires to the alternator( from B+ to the alternator)... about the idle problem... it may be your TPS throttle pos sensor... it may missread the driver demand (gas pedal) when it gets warm or hot.. by shutting it off it gives it some time to cool...or it could be you cables to the throttle check for any looseness, it should be free of any other components...its about $32 on GMPARTSDIRECT.com part 17123852 wont hurt to change that not to expensive too..

Had the same darn trouble with my 96. It was the throttle position sensor.

Here's an old post from another board:

"Get a spray can of Throttle Body Cleaner (not carb cleaner) from AutoZone or similar. Remove the airbox and the hose going to the throttle body (make sure the MAF is out). Shoot throttle body cleaner at the throttle body, Use an old toothrbrush or similar to loosen the crud, and use a rag to wipe it up. Be sure to rotate the plate and clean the backside as well (the brush would come in handy here)."

Seems to be a common fix for not only the Aurora but other makes as well. Do you know if your dealer has tried this yet? I think the sensor is doing it's job seeing as it triggered the MIL due to to the steeper than commanded throttle angle.

As for the flickering lights, not sure other than maybe an oxidized connection at alternator, fuse block, or internal to the multifunction switch which can also be cleaned.

did you try to have him check the ignition coils?