Engine is revving up without input

2003 CADILLAC DEVILLE
111,200 MILES • 4.6L • V8 • FWD • AUTOMATIC
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RP PERRY
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  • 11 POSTS
Engine throtttle has mind of it's owns.. The engine RPM's will increase without any action from the driver, the only way to stop it is to ride the brakes

This car has the throttle with cables. The North star V8.Engine When the vehicle has cooled down the car will start, run fine and drive OK until the engine warm. I have a OBD11 don't have any codes. Checked for vacuum leaks found none. Removed throttle body checked and clean, replaced (taps) and (ac) o rings with no results.

Obtained like vehicle swap parts one at a time with no change. Yes I swap the (pcm) too. I need some help.
Jan 9, 2015 at 11:49 PM
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WRENCHTECH
  • ✓ASE Certified Mechanic
  • 20,761 POSTS
  • ASE Certified Mechanic
First eliminate all vacuum or air leaks in the system. You may have a bad IAC ( idle air control) but try cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.
Jan 10, 2015 at 5:52 AM
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RP PERRY
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  • 11 POSTS
engine vacuum leaks are repaired. I used the propane and smoke test to confirm no leaks. Replaced the (IAC) with a new one. Still have the same problem.
Jan 15, 2015 at 6:24 AM
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