Hello to all purchased a 1993 Z28 5.7 Automatic a few days ago , I am having trouble with the TPS signal. I have installed 3 TPS sensors, the first one failed right out of the box good power supply no output voltage. The second one at closed throttle read .80 vdc wide open throttle 3.88 vdc. The third one .067 vdc idle and 4.20 vdc wide open throttle. When I started the car the voltage jumped all over the scale and it is running very rich.

I have troubleshot and repalced the EGR valve stuck open and the fuel pressure regulator fuel in vacuum line. I have installed new plugs, wires and optispark and water pump as well a wp drive gear.

The TPS sensor when applying throttle with the engine running jumps all over the scale.
Is it a common problem on these models to have the TPS wires fail in the ruturn to the PCM ?

 

try replacing the plug on the wiring side. the clip connectors inside it get worn and can fail. if the readings you posted are constant the computer could adjust or you can adjust. simply inlarge the screw holes a bit. i currently use an adjustable tps i picked up from tpis

 

Thanks for the information I'll replace the pigtail and I had thought of adjusting the upper screw hole just was not sure if it was ok to do.