Fast Idle was...TPS???
Thread Starter
Pro
Joined: Oct 2003
Posts: 732
Likes: 2
From: Baxter MN
Fast Idle was...TPS???
Took the '91 in to a reliable and honest Chevy dealeship in Staples, MN. Terrible idle - 2000 rpm warm in neutral, 1200+ in Drive or Reverse. After just a very short time I was told it was my TPS unit. Asked if I wanted a GM part or if aftermarket was aceptable to me. Went with an over-priced NAPA unit, total of two hours of labor and the car ran flawlessly.
Plus, while I was trying to do some of this work muself I eliminated the heater hoses to the throtle body as unnecessary clutter. Just as most others on this forum have said, that single modification must be worth a good 40 - 50 SOP HP .
Anyway, if it helps anyone else out, I never suspected the TPS. I went after the IAC, stood on my head (practically) trying to find vacuum leaks, etc. The TPS could have been replaced by myself in 10 miunutes if I had thought it was the culprit.
Oh well...live and learn.
Glen
Plus, while I was trying to do some of this work muself I eliminated the heater hoses to the throtle body as unnecessary clutter. Just as most others on this forum have said, that single modification must be worth a good 40 - 50 SOP HP .
Anyway, if it helps anyone else out, I never suspected the TPS. I went after the IAC, stood on my head (practically) trying to find vacuum leaks, etc. The TPS could have been replaced by myself in 10 miunutes if I had thought it was the culprit.
Oh well...live and learn.
Glen
Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
Two hours for a TPS? That's well over $100 labor at a dealership. Yours is non adjustable right?
I had an intermittent high idle problem as well. It was my TPS sometimes giving a false high reading making the car idle at about 1,800 rpm. A bad TPS can indeed cause a high idle problem. Caught it giving a false high reading using a multi-meter. Fixed it and never happened again. I first though it was a sticking TB, but it wasn't.
I had an intermittent high idle problem as well. It was my TPS sometimes giving a false high reading making the car idle at about 1,800 rpm. A bad TPS can indeed cause a high idle problem. Caught it giving a false high reading using a multi-meter. Fixed it and never happened again. I first though it was a sticking TB, but it wasn't.
Melting Slicks
Joined: Aug 2006
Posts: 2,191
Likes: 243
From: Guelph Ontario
Maybe a TPS
Coming into work from Guelph to Kitchener on the 401 up here in Canada and all of a sudden my 86 C4 started running like a bag of snakes---coughing and farting but still drivable. Got to work ---opened the hood --nothing obvious. Came back out at lunch and fired it up and it ran OK. Got home and read the codes---Code 55 and voltage high at TPS code....Checked this web site and got some valuable info on checking the TPS switch---don't know if my Fluke clamp on meter goes that low in VDC??? (.525) But all of a sudden it started running fine after adjusting the TPS--idles good--runs strong--I have sent away for the connection between wiring and TPS--don't want to short any thing out playing around with connectors. The scary part is that I did't find anything???? And it is running good. There was a good link I got off this site to check resistance in the TPS itself---THANX to who ever posted that one!!!
