Help! My 02 Monte SS wants to idle at 1500 to 1800 rpm on cold starts and up to 2300 rpm once she warms up. If I restart her sometimes she will idle at 750 to 900 rpm but that is random. The check engine light is not on and there are no codes stored in the pcm. The air filter is clean and my plugs are ok. But I bought new ones anyway. The engine is stock. This started about 2 weeks ago. I also lubed the throttle body springs and the throttle cable doesn't seem to be sticking. When driving, rpmz stay at 1500 when I take my foot off the gas until I come to a stop, then drop to 900.
This is a weird problem that I have not seen in any other GM I have owned so I Really Really need some help! Please? I know what it is doing to my gas mileage and hate to think of how it's effecting my brakes :-( Can anyone point me in the right direction.? She's my baby! :'(

 

you sure the check engine light actually works?(should turn on for a quick
moment when starting the car)

The only things I could think of is a throttle position sensor(tps) or a leak in the emissions system.

 

Red Nightmare: Thanks for the reply! Yes I'm sure. Had the computer programed in April. When I when to have her inspected she had a Buick program. Had Pepboys do a read for me. They found no codes. I was thinking TPS or IAC or a vacuum leak like you suggest.
Was hoping this had been seen before so I don't spend $$$ on parts that don't fix the problem. I will test all her intake sensors!

 

You can try cleaning the sensors, even try removing the TB and cleaning that, the plate might be getting stuck open from caked on carbon.

 

Hi guy, haven't removed the throttle body yet but I found the IAC dirty and the grommet for the MAP sensor was cracked. Took care of those and the idle has getten closer to normal. But it's still hi. Tomorrow I'll tackle the throttle body and Chechen for vacuum leaks.
Does anyone have a Vacuum Diagram?

 

Cleaning out the throttle body and MAF should help out a lot. I noticed a much smoother idle after cleaning mine.. Mine looked like it had never been removed in any of its 75k miles, was well over due for a cleaning.

As for a vacuum leak, the tube that comes from the throttle body to the FPR (Fuel Pressure Regulator and a various sensor) is likely to crack. Mine cracked when I removed it once. I tried to be careful with it but it was pretty fragile which I kind of expected since it was 11 years old.

 

I was going out the do laundry. Started YelloJAC up and she went to 2300 right away. (Cold start) So I shut her down, popped the Hood and started her with the remote. I notice that she was sucking air like a whale thru a blow hole. So I took off the air filter and she ran great. Check the air filter (stock frame filter) and found it full of sand. Got it all out and she been running like a Good SS all day. Guess my Christmas gift to her will be a cool are induction system. Thanks to everyone for the help with this! ;-)