Skylarking
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Paul, it sounding like your throwing parts at it rather than diagnosing what is actually faulty… by testing cables, doing sweep test, etc… As is, from what I understand you’ve still got the intermittent problem and you haven’t tried installing the used APPS yet…
One can’t shortcut a diagnosis by throwing parts at it unless it’s known issue with specific vehicle and it’s known that failed accelerator pedal assembly or throttle position switch are the culprit (which in some GM vehilce is actually the case). But again which one could it be,… testing should give hints… else both must be replaced (which may not be a bad idea from a preventative maintenance perspective).
But replacement in such cases, where sensors wear out through use, it’s best not to buy second hand (unless they are known to be low kms unit but the problem is everyone only drives to church on Sunday). Buying high milage second hand sensors will probably be just be buying someone else's problem
So I still think you should check wiring (unplug connectors from ends of loom and use an multimeter and measure each wire resistance while wiggling cable, then measure to each wire to earth which should be infinity since the connectors are unplugged)…
How to test sensors, well such sensors are simple variable resistors and thus use an input voltage (+5V) and have two output voltages one sweeps up (~0-~5V) and the other sweeps down (~5-~0v). So they can be bench measured by manually feeding the input voltage and operating the shaft the sensor is attached to… As the shop manual indicates, slow sweeps checking output voltage is nice and clean and fast full travel sweeps doing same… usually an analog meter is better for such… To bench test the comparative outputs, just conext yje meter +ve lead to one output and the negative lead to the other output. The sweep will go from ~5V -> 0v -> ~-5V as the shaft is turned and it should be smooth and symmetrical as the shaft/pedal is moved through its limit. The later test isn’t 100% accurate as it doesn’t check voltage and comparative voltage against angle but smooth and symmetrical movement of the meter needle is a good indication…
Hope you can find out what’s is the root cause and get it all sorted… but slow down and test things according to the workshop manual is the solution… You may get lucky throwing parts at it but usually it’s just throwing money away when it could be spent on test tools
Hope you get lucky and the APPS fixed your woes
One can’t shortcut a diagnosis by throwing parts at it unless it’s known issue with specific vehicle and it’s known that failed accelerator pedal assembly or throttle position switch are the culprit (which in some GM vehilce is actually the case). But again which one could it be,… testing should give hints… else both must be replaced (which may not be a bad idea from a preventative maintenance perspective).
But replacement in such cases, where sensors wear out through use, it’s best not to buy second hand (unless they are known to be low kms unit but the problem is everyone only drives to church on Sunday). Buying high milage second hand sensors will probably be just be buying someone else's problem
So I still think you should check wiring (unplug connectors from ends of loom and use an multimeter and measure each wire resistance while wiggling cable, then measure to each wire to earth which should be infinity since the connectors are unplugged)…
How to test sensors, well such sensors are simple variable resistors and thus use an input voltage (+5V) and have two output voltages one sweeps up (~0-~5V) and the other sweeps down (~5-~0v). So they can be bench measured by manually feeding the input voltage and operating the shaft the sensor is attached to… As the shop manual indicates, slow sweeps checking output voltage is nice and clean and fast full travel sweeps doing same… usually an analog meter is better for such… To bench test the comparative outputs, just conext yje meter +ve lead to one output and the negative lead to the other output. The sweep will go from ~5V -> 0v -> ~-5V as the shaft is turned and it should be smooth and symmetrical as the shaft/pedal is moved through its limit. The later test isn’t 100% accurate as it doesn’t check voltage and comparative voltage against angle but smooth and symmetrical movement of the meter needle is a good indication…
Hope you can find out what’s is the root cause and get it all sorted… but slow down and test things according to the workshop manual is the solution… You may get lucky throwing parts at it but usually it’s just throwing money away when it could be spent on test tools
Hope you get lucky and the APPS fixed your woes