High idle which fluctuates up and down?

DREWATS

MEMBER
1996 PONTIAC BONNEVILLE
6 CYL
FWD
AUTOMATIC
168,000 MILES

When I start my car in the cold weather the vehicle has a high idle which fluctuates up and down sporadically between 1500 rpm and 3000. I replaced the throttle position sensor I was told if you unplug the sensor and the problem stops then the sensor is bad but I replaced it twice and it did it with both new sensor. Also when I leave my driveway which is at on end of the block and I drive to the stop sigh and come to a complete stop, idle drops to just under 1000 and idles fine after

4 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Clean out the idle air control valve and see what happens.

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Wednesday, May 26th, 2010 AT 4:38 PM

DREWATS

MEMBER
2 POSTS

I forgot to post that I replaced idle air control valve as well and sprayed down the throttle body best I could but didn't take it off. I was also told my be a vacuum leak I replaced whatever hoses were visible on top of the engine

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Wednesday, May 26th, 2010 AT 8:11 PM

OKIE_777

MEMBER
3 POSTS

Was your issue resolved, and if so, can you report how?

I’ve been having similar issues. Thanks.

(I’m aware this was 13 years ago but I’m hoping you remember lol)

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Sunday, October 22nd, 2023 AT 8:48 PM

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

Because of the thread's age, I suspect you won't hear from the person that originally posted it. Is your vehicle the same year, make, model, and engine? If so, let me know exactly what is happening and I'll try my best to help.

Take care,

joe

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Sunday, October 22nd, 2023 AT 9:14 PM