good idle, no throttle

CK. TPS. sensor and wire leading to it.

 

Might be more of a mechanical issue with the tps....check mounting.

 

what codes did you get?

 

You may check the round connector coming out of firewall to ECM. We have found wiring issues there on the older trucks. Usually a wire broke in side the insulation and you can't see it. I would do a pin test from TPS connector to ECM commector with a DVOM. Unplug the TPS sensor first with check for 5volts reference voltage and ground with a meter. the thrid wire will be signal from the TPS and will show nothing unplugged. Once you verify power and ground check sigan voltage by gently probing sig wire with test lead and the other to ground. Slowly push down on pedal and voltage should change slowly and gradually. This will tell you if you are missing power from ECM or ground. If the signal voltage is ok then you know your problem is in the signal wire from TPS to ECM.

The truck side of TPS connector is where to check these voltages not the sensor side.

 

Hi wore out,
Is it my bad luck or are we finding more wires broke inside the insulation lately? I have found such wires at least 4 times in the last year(