Thread: 2001 Grand Prix SE idling erratically

Hi all! My 2001 Grand Prix SE has started to idle erratically here in the last few weeks. It's most noticeable when I'm stopped. The idle will go from about 7-800 RPM down to 2-300, like it's about to die. It has died once already at a red light. At highway speeds (50+ MPH) I'll feel it "buck" frequently. I haven't noticed any bad smells. It idles like this when the engine is cool or warm, it doesn't seem to matter. I've changed the spark plugs/wires, but haven't changed the air filter/fuel filter in awhile. Assuming these aren't the cause (my luck is never that good), what else could it be? The engine is the 3100 V6 with 140,000 mi. Any suggestions would be great!
Love the forum!

He said pull out...

Air filter, Air temp sensor, iac valve, maf sensor. Clean em.

Fuel filter. Bad batch of fuel. Dirty injectors.

Where is the MAF sensor? Also, can I just use a throttle body cleaner spray while leaving the body intact?

Uh huh huh huh "pull out"....
Where is the sensors and the IAC valve? And thanks again for your suggestions!

#13 MAF #29 IDLE AIR

Temp sensor is on the rubber elbow coming from your air intake box.

I wouldn't use carb cleaner on the MAF, unless you WANT to buy a new one.

Use electronics cleaner.

Ok, I'll give this a shot. Trying to replace the fuel filter, stupid me didn't think about one end of the filter having the plastic clip connection. I'll give it another go today, now that I have the proper tool.

*UPDATE* I got too frustrated with the fuel filter to replace it myself-it didn't look like it had been replaced since even before I had the car, and the metal fuel line on one end of the filter was too hard for me to break loose without stripping the nut. If the idle problem persists, I'm going to try cleaning/replacing the sensors.

Lol, I just changed my filter the other day and had a hell of a time.

Got it though. PB Blaster ftw.

Cleaning the sensors is easy.

Also, dump some Lucas or Gunk in your gas tank.

Sound to me like a dirty sensor, since you're not getting any codes.

I have gotten a EVAP code before, but that was before the idle problem. Still, I wonder if the IAC valve or the MAP sensor would be what was setting it off. I doubt it, though, since the mechanic who ran the diagnostic said it was somewhere around the fuel tank...Still, I'm going to try to clean/replace the sensors. Later I'm going to try to post a pic of the engine and make sure I have the right sensor in mind before I pull it.

I was just wanting to make sure if this was the MAP sensor in the pic, the one I have circled in red.

http://i965.photobucket.com/albums/a...k26/Engine.jpg

Holy jeez. I know nothing about the 3100s.

Tonkinonlineparts.com

#2

LOL! I know, that's kind of why I put that in the original post. There's an abundance of info on the 1997-2003 Grand Prix with the 3800, but unless you just Google "3.1 GM V6" or "3100 GM V6", there's next to nothing specifically on the 1997-2003 Grand Prix with the 3100. Still, I think the diagram helped.

Good news, though: since I had the fuel filter replaced, the idle problem has almost disappeared completely. It still idles down at stops noticeably, but after I'm stopped, it runs/idles fine.

How's your air filter? Did you clean up those sensors?

Dump some fuel cleaners in your gas tank.

I just replaced the air filter. I've been so busy with work, I haven't gotten around to cleaning the sensors. Thanks for all your help BTW!