95 Grand Prix idles too fast


tnman
09-18-2003, 09:00 AM
My 95 Grand Prix , has just started idling too fast. When I start it up the rpms jump to 2500, then drop down to around 1900 which is way to fast. Normally it will run around 1000. Any ideas? Thanks

Cokeroker
09-18-2003, 12:43 PM
try replacing your throttle positioning senser (pretty cheap and easy to do yourself)

tnman
09-18-2003, 02:12 PM
try replacing your throttle positioning senser (pretty cheap and easy to do yourself)
I tried this along with the idle control sensor and neither one fixed the problem. Any other suggestions out there?

Cokeroker
09-18-2003, 02:55 PM
when you replaced the throttle positioning sensor: does your car now jerk when you put it into drive or reverse? If it does, and easy mistake with the TPS install is putting the levers on the wrong side and it kicks it up pretty high.

tnman
09-19-2003, 04:51 PM
My 95 Grand Prix , has just started idling too fast. When I start it up the rpms jump to 2500, then drop down to around 1900 which is way to fast. Normally it will run around 1000. Any ideas? Thanks

I finally broke down and took it to a shop. He said the Idle control sensor I installed was not adjusted right, however, I adjusted as the instructions stated. He told me the instructions were wrong, it said to adjust the spring to 1 1/8" when it should be about 7/8" of an inch. $110.00 for him to fix it. :(

92GPSE24VTDOHCV6
11-18-2003, 06:39 PM
Did that work? I had the same problem, and it was my upper and lower intake gaskets...or I got scammed...hmmm

tnman
11-19-2003, 08:33 AM
Did that work? I had the same problem, and it was my upper and lower intake gaskets...or I got scammed...hmmm

Not sure what actually worked. I had to make 3 trips to the dealer before they got it fixed. I know for a fact they did not replace the intake gaskets. The service manager was gone for a week the last time I picked up my car and havent' called him back to see exactly what the problem was.

Phill Acio
11-19-2003, 10:40 AM
Hey if you find out what was wrong with your grand prix can you post it? Im having the same problems. My car idles real high. It either runs normal or is idling at 2000 rpms.

grantmon
01-24-2006, 09:25 PM
I have the grand prix 3.4 L engine and also have been getting a fast idle on cold starts.It idles at about 2000 at the start and can fluctuate up to 2500 or 3000 before is warms enough for the RPM to come down to around 1200 and when it is completely warmed up it comes down to about 700 at idle and runs great. I replaced the idle control motor myself. Cost $60.00 CDN. It is a sealed unit and there were no instructions about adjusting the spring. I assume the spring is the right size as it is a complete unit made for my model and year. I am still having the proplem although not as severe. I am thinking it may be a faulty temperature sensor sending the wrong information to the computer which then sends incorrect info to the idle speed control motor. Any Help out there for me?

grantmon
01-24-2006, 09:37 PM
I have the grand prix 3.4 L engine and also have been getting a fast idle on cold starts.It idles at about 2000 at the start and can fluctuate up to 2500 or 3000 before is warms enough for the RPM to come down to around 1200 and when it is completely warmed up it comes down to about 700 at idle and runs great. I replaced the idle control motor myself. Cost $60.00 CDN. It is a sealed unit and there were no instructions about adjusting the spring. I assume the spring is the right size as it is a complete unit made for my model and year. I am still having the proplem although not as severe. I am thinking it may be a faulty temperature sensor sending the wrong information to the computer which then sends incorrect info to the idle speed control motor. Any Help out there for me? How do you adjust the spring?

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