1991 Deville, high idle until vehicle stops !

[swerling]

1991 Deville 4.9, the idle speed remains high until the vehicle comes to a complete stop. This make stopping the car a real adventure. Also, after a complete stop all you need to do is accelerate slightly and the car will speed up to 30MPH on its own without your foot on the pedal.

[MarkC]

have you checked the throttle linkage for binding/sticking or the return spring?

[swerling]

all the linkage seems fine. I did get a TPS error that I cleared a few days ago and it has not returned an E55 which is a TPS out of adjustment error.

[636neil]

Replace the throttle control motor.... It's located at the air intake on top of the motor.... Can get the part at Auto Zone for about 60.00.. Don't drive it like this for very long because it will screw up your brakes and warp your rotors due to the power this engine has.

[DFBonnett]

First thing I would do is remove the air horn then open the throttle. Look at the throttle bore and plates. If they are full of gunk, spray them with oxygen sensor safe (read the can) carb cleaner and brush with a tooth brush. Repeat as necessary. Spray to rinse. Reassemble the air horn. Disconnect the negative battery terminal for 30 seconds then reconnect. Start up and see if it is better.

[shadowman69]

I was wondering if anyone have a 1991 Cadillac Deville starter wires diphram. Plz get back to me soon as possible.

[caddydaddy]

What in the wiring are you looking for? I have the diagram for a '94 4.9, which is the same.