Here is how i would test the TPS. Disconnect the connector at the TPS and measure voltage on the harness side with key on.
Y/R wire-------12 volts
G/B wire-------Ground
G/Y wire-------5 volts
Plug connector back on and read voltages
Y/R wire-------Throttle closed----0 volts
Throttle opened----12 volts
G/W wire-------Throttle closed----.05 to .08 volts
Voltage should increase smoothly as throttle is opened to full position.
If the first set of tests are good and one of the second set of tests fail, the TPS is bad.
Conner

Over the hill but still climbing.
88 Montero 2.6L auto, manual hubs, cooling fan conversion gps,recurved distributor,LSD Diff.