I know this may sound stupid but it has happened to me. Do you have gm floor mats in the car? Make sure that it isnt rolled up unto the gas pedal. I know everyone is saying is this for real, but it did in deed happen.

Good luck,
Sellncars

Nope can't say I do, that is definately not the problem. The more I think about it, the more the throttle body being gunked up makes sense, so I will clean that this weekend and see what kind of results I get.

I had the high idle (2500rpm) when cold problem and it would drop down a bit after driving a while but felt like the cruise control was stuck on sometimes.
Fixed it by making the TPS adjustment shown in this article. ttp://www.geocities.com/carnutguy/cars/tpsenhancement.html
It is pretty simple to do and costs nothing except a couple of small washers
My guess is that the TPS sensor goes faulty (high resistance), and the voltage it sends to the computer is out of a range that the computer can work with. I had a low reading at idle and this adjustment brought it back up and fixed the problem

I'm thinking this may be the culprit as well. Try giving your TPS a twist counter clockwise when it'* revving like that.

I think John is on the right track here. A TPS or MAF will throw a code and a light 99% of the time. But a sticky butterfly, or even more likely, a sticky or gummed up IAC (in the TB) would be likely culprits. I'd remove the TB and give it a thorough cleaning with the MAF, TPS, and IAC removed, then gently clean the MAF with rubbing alohol, lightly oil the shaft of the TPS, and scrub the living snot out of the IAC and TB with intake cleaner and a brush.

there is a seafoam spraybottle that can be used to clean ur tb... ive never cleand the throttle plate on my bonneville (but i have on a 4.8liter v, but i would just use the cheapest carb/choke cleaner... leave ur car off, open the throttle plate to wot (u can have somebody in the car press on the gas or u can hold it open at the side) spray the throttle plate with the cleaner and wipe it off with a shop rag or a paper towel(be careful if u use a paper towel).

Don't use carb cleaner in that manner. You can kill your MAF and O2 sensors. Use only 'intake safe' cleaners or those advertised as 'sensor safe'.

In any case, that'* not enough to thouroghly clean the TB. I suggest removing it, stripping it down, and really getting in there. Even if it'* not the problem, our TB'* are NASTY inside at 50k miles. Your car will benefit from this, and it'* not wasted effort.

Pouring anything through the PCV will do nothing for the TB as the PCV is down stream of the TB. You have to scrub the bore and butterfly (particularly where they meet) through the intake.

FWIW, I have used good ole Gumout carb cleaner on the TB and never hurt the MAF or any O2 sensors. Don't get silicone anywhere near the intake. That is sure death to an O2 sensor.