watchinfaith07

Hello all, hope all is well- i have a 1999 Chevy Lumina 3800 model, with 254k miles on it. Ive recently been having problems with the idle- basically, whenever i would come to a stop, with the car in drive, the RPM's would slip from 800-1000 sharply down to 400, then back up to 900-1000. My lights would dim, and the engine would sound as if its about to stall out. that occured for about a week. also, when i would come to a stop, then go to accelerate, the engine would buck and the RPM's would ruise and fall quickly. When i would shift into park, the rev would go to 1500, then fall all the way down and stall the car out.

I took my car to my mechanic, and he replaced my fuel filter and fuel pump, saying i had no pressure. ($600 total to repair) i get the car back the other day, and its still doing the EXACT same thing.

I am just wondering if anyone has any advice (besides junk it lol) or has similar experiences as to what could be causing this.

Thanks in advance for any and all help!

Bigbronx72

I had the same issue and it was my IAC motor (idle air control).

gasteffens

I would find a new mechanic, first off.

It could definitely be a problem with the IAC, or also a dirty MAF (Mass air Flow) sensor. It could also have a vacuum leak. In my experience with those 3800s, they are pretty tough to kill but miles and age catch up with the little wearable items.