High idle delayed shifting

KYMMIECOO

MEMBER
2003 BUICK LESABRE
3.8L
AUTOMATIC
95,000 MILES

On November twenty fourth while driving my car started idling high, I made it home and the check engine light came on. I had a code reader hooked to it and it told me it was the TPS had it changed and code cleared. Drove fine for about two weeks and started doing it again. I unplugged the battery for a few hours, but when I hooked it back it seemed the idle was worse than before. So I changed the TPS again, still doing the same thing. I had the throttle body taken off and cleaned really good. And it is still idling high. Sometimes it accelerates on its own. Very scary because I do not know if it is going to leave me stranded. Had a diagnostic computer hooked up to and it said I have my foot on the gas and it was still giving TPS as my problem. Any clues where I should go next with this?

1 Reply

HARRY P

MECHANIC
2,292 POSTS

Scanners and trouble codes do not tell you that a sensor is a problem. They tell you to check the circuit as a whole, which includes the sensor. Check the wiring to the TPS. Look for bare spots on it as well as brittle wiring. If you have a multi-meter, take the lead wire from the TPS and run a continuity check between it and the negative battery terminal. Do the same with the signal wire. If there is continuity (meaning a meter reading of 0 or close to it), then that means that the wire is shorted to the ground.

You can also use a multi-meter to see if there is a spotty connection in the lead and signal wires. Basically you will hook up the multi-meter and start jiggling the wires a little bit while watching the meter. See what happens.

Let us know what you find.