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Chuck Banks
08-04-2023, 07:20 PM
My '92 with 101,600 miles just developed a drivability issue that I think may be related to the TPS. Upon start up with engine cool, throttle response is instant, and car has good power. When engine is fully warmed up, (easy to achieve here in AZ,) there is a hesitation on first pushing the throttle, and it seems to take a moment for the engine to develop full power. If I'm at part throttle and quickly press the pedal, there is no hesitation and car performs as it should. It has also developed a surging when off the throttle and coasting to slow down. If I keep giving it a little throttle when coasting the surge is not as noticeable. The car is not showing any codes, so I'm not sure if it would only show a 21 or 22 code if the TPS was completely inoperable.
I've owned this car for 31 years and done almost all maintenance including new Accel injectors at 92,000 and then new starter at 94,000, and Fuel pumps and sender at 100,000. I think things are just getting old and maybe thats whats causing the driveability issue.
Any thoughts on my failing TPS diagnosis. I don't have a tech 1 so would have to figure out how to set the TPS if I replace it.

Thanks, Chuck

secondchance
08-04-2023, 10:36 PM
I would remove the TPS, rig volt meter to it and slowly move the lever observing the voltage. If the voltage moves progressively, good. If it spikes and fluctuate, bad TPS. My original TPS was worn around 1500 to 2200 rpm. Understandable?

Chuck Banks
08-05-2023, 01:01 AM
Will test the sensor this weekend as you suggested.
Thanks

secondchance
08-07-2023, 09:34 AM
Actually, in the abscence of reference voltage, I might have checked resistance.

Young1
08-09-2023, 08:06 PM
And it is an easily procured GM part. Yeah!

Chuck Banks
08-10-2023, 07:37 PM
Tested the TPS off the car using an analog ohmmeter. The sweep of the needle was uneven from the idle position for a short distance before it became smooth for the rest of the travel of the arm. I replaced the TPS with one from Standard Motor Products. Problem seems to be resolved. Thanks for the tip on checking the TPS.

secondchance
08-11-2023, 11:03 AM
Tested the TPS off the car using an analog ohmmeter. The sweep of the needle was uneven from the idle position for a short distance before it became smooth for the rest of the travel of the arm. I replaced the TPS with one from Standard Motor Products. Problem seems to be resolved. Thanks for the tip on checking the TPS.

Exactly the same had happened to me about 4 years ago. A new TPS and the problem was solved.