Mechanics

GRAND HIGH IDLE PROBLEM

1989 Mercury Marquis

I have a 1989 mercury grand marquis with a 5.0 in it with tbi.I started it the other day and it seemed to warm up normal then it started to idle high and does so all the time now. Any info or ideas would be great, thanks.
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Bigcountry625
April 17, 2007.




May shure there are no spark plug wires trapped under the throttle. Look at the throttle for free operation. If thats good check the throttle cable, and then the temp sensor, (ETC). Lastly check the idle air control (IAC) it's bolted on the side of the throttle body.

Merlin2021
Apr 19, 2007.


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