It'* been bitter cold here (2 degrees F) The first thing in the morning when I start my 1996 Bonneville I experience a high idle. It starts out at 1500 rpm and climbs to 3000 RPM. After the car warms up and I put it into gear and drive it for 10 seconds, the idle returns to normal (in neutral and in gear) It'* a new engine, when I replaced the motor, I replaced the MAF and MAP sensors. This has just come up and the motor doesn't even have 10,000 miles on it. Any suggestions?

The solenoid on your IAC Valve is probably stuck open. The IAC controls that initial idle.

I'm not familiar with the IAC, I'll check it out.

Try here. It'* really called the idle air control valve.


http://www.alldatadiy.com/alldata/AF...57342/34857358

I did replace the IAC too. The original one was full of carbon; since it was relatively cheap I replaced it. I will check it out though.

Mike

hmm... that would be by only guess unless you have a vacuum leak somewhere. Did you do any recent work to it?

The last work was putting in the new engine. It'* a brand new 99 GM Crate motor. New Intake (with the stove pipe fix) The only thing that was reused were the fuel injectors and the coil packs. I remember before I replaced the IAC on the new motor (the old motor before it threw a rod) had a high idle problem, I'll check out the IAC, maybe the O-ring isn't seated properly.

I too have a problem with a high idle on my 96 only the car runs @ 1500 and stays there until you kick the pedal, then it goes down.
If you are jumping up to 3000 something else is wrong like a bad temp sensor, vac leak, or maybe the inlet air temp sensor is bad.

My idle was stuck at 3,000 rpms no matter what I did when I put everything back together after my LIM gasket install. I put the Throttle Body positioning sensor on wrong and it was actually holding the throttle body open a little, but enough to give it a really high idle.

Yup, battled that issue with my 99 SE too. Was still doing it when I sold it with 177,000 on it this past summer...

My brother'* 2003 Grand Prix with 122,000 does it too. Very odd to say the least.