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2000 Grand Prix 3.1 fast idle

R

russcycles

New member
My 2000 grand prix 3.1 sometimes idles fast at startup. sometimes 1500 to 2000 rpm. shutting engine off and on a few times sometimes gets idle to return to normal.

When I disconnect the throttle position sensor when the engine is idling fast, it casues the idle to return to normal. but trying to drive with the TPS unhooked causes the tranny to not shift right.

Is the TPS bad? Thanks.
 


Is the check engine light on? Mass air flow meter, coolant temp sensor, air charge temp sensor, stick iac motor....There is all kinds of stuff that can cause this. You can clean air flow meter and throttle body. I would not advise cleaning the tps.
 
I cleaned the idle control valve and drove the car and it seemed ok so far.

Note: With the idle control valve out, don't test it by hooking it up to its connector and turning on the ignition. I tried this and the valve itself popped out of the body and fell to the ground. Fortunately, I found the valve and put it back together and it still works. LOL!
 
COEBAM said:
Is the check engine light on? Mass air flow meter, coolant temp sensor, air charge temp sensor, stick iac motor....There is all kinds of stuff that can cause this. You can clean air flow meter and throttle body. I would not advise cleaning the tps.
Click to expand...
I bought the car in jan. 2008 and the check engine light was on and has always been on since I've had the car. The fast idle problem started after taking the car to a Jiffy Lube for an oil change. I took it back to the Jiffy lube when the fast idle started as I thought they may have messed up the throttle linkage when they replaced the air filter. The tech hooked their diagnostic device to the car and when he reset the computer then the idle returned to normal. If it idles fast on startup, I sometimes disconnect the battery for a few minutes and I guess that resets the computer and the idle goes normal then until some future time it acts up again. Thanks for your reply.
 
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