1992 Cadillac Deville Idol speed control

REARDRIVE

MEMBER
1992 CADILLAC DEVILLE
4.9L
V8
FWD
AUTOMATIC

I put a new idol speed control on when the engine is idling it don't seem to be running to loud but when I come to a stop it seem like the motor is idle up more I screwed the screw on the ISC all the way in but that didn't change a thing and when I am driving I can feel the accelerator study bumping my foot when I turn the car off I can hear tapping noise coming from under the hood how can I fix this problem?

3 Replies

HMAC300

MECHANIC
48,601 POSTS

Have a pro listen to the engine to see if he can see what tapping noise is 4.9L is known to be a bad engine and has a myriad of problems. Also clean throttle plate on both sides and idle control hole with choke cleaner.

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Tuesday, May 19th, 2015 AT 5:42 AM

REARDRIVE

MEMBER
93 POSTS

The tapping noise is coming from the idle speed control I can see the gas pedal going up and down what need to be done fix that problem can you tell me how

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Tuesday, May 19th, 2015 AT 6:10 AM

HMAC300

MECHANIC
48,601 POSTS

Did you drive it after replacing it? They have to be driven at 40 mph for at least a mile to set right. It should have been set at a specific distance prior to install as well. Was it doing it prior to the new iac solenoid?

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Tuesday, May 19th, 2015 AT 6:31 AM