Does anyone know a fix for my 96 vinK bonne?
Cold start below 40deg the idle hangs at 1500.
It will not come down unless it runs 2min and you kick the pedal
(like a carb).
Above 40deg. starts and comes down fine?
Changed swapped temp sensor and IAC. Didn't work.
Bought a GM 96 drivability service manual and it said at cold start
the car is in open loop and only uses the temp., tps and maf sensors.
Does anyone else have this weird problem?

Until the cat heats up your open loop control, after the cat heats it returns to closed loop. Is this something new that has just developed, or something you've just noticed? You may want to look at the exhaust for any leaks before the cat?

I picked up the car in June 03 and never had a problem all summer until the
cold weather came around. Its only doing it below 35 -40 Deg.

Thanks,
Also where is the open loop control / sensor?

I think that is perfectly normal behavior. That keeps the car from stalling out. Every Bonneville I have driven in the winter does that.

Another good way to verify correct idle rpm is to use a scantool to see that the PCM is requesting 1500 idle rpm when cold.

Hello everyone,
Yes but if I start it and walk away it will hold 1500 rpm indefinitely.
Shouldn't a computer controled engine eventually idle down by itself.
Yes its not that big a deal for me to kick the pedal I also drive an 80 Buick
with Carb.
The problem is when my daughter uses the car and I hear it racing in the driveway
when she forgets to kick it down.
Does anyone know if the TPS signal could be affected by the cold?

After a period of time it should come down to around 650. The throttle body plate can get stuck if it'* dirty. A dirty throttle body would be my first guess, then I would check for proper IAC valve operation. That can get gummed up as well, however when you clean the throttle body you have to make sure you clean the IAC valve passage.

been there done that. The car ran smoother but still 1500.
My intake started leaking shortly after cleaning although the dealer told me its
perfectly fine to use carb spray.
I called a second dealer and he said to spray it on a rag and wipe the throttle out.

Carb spray is BAD news on your intake. Don't even consider it. Even intake safe cleaner requires the removal of the MAF sensor first. If you did this, you may need to replace the MAF.

So in the future what should I use to clean it?