Throttle positioning sensor nightmare

[Zan Stout]

We replaced the throttle positioning sensor on a 1993 Olds ninety eight and the ECM is still coding a 21 (TPS circuit singnal voltage high). We have checked all the wires to and from the TPS to the ECM, have tried adjusting the position of the TPS to no avail. The CEL comes on after about a minute or so and rough idle begins. Please Help!

Thanks,
Zan

[joe4speed]

I have the same problem with mine. I replaced it about 3 years ago, then it went bad again and affected the idle, gas mileage, and transmission. So I put another one in about 3 weeks ago and now it's doing it again sporadically. I can't figure it out either.

[Hansnet]

put a dmm on it Terminals A and C tell me what the idle voltage is.

[lalahg]

Sorry for replying to such an old message, but this may be relavent for others searching through the posts:

Did you check the voltage after installing it? My engine ('92 3.8L) requires the voltage at idle to be between 0.36-0.46 volts.

I had to replace this sensor twice (coincedently right after a spring cleaning under the hood, hmmm). First was with an el-cheapo sensor, second with AC-Delco. I had to bend the arm on both to get the voltage under 0.46 volts!