How do you test a tps on a 1990 miata?

Answer 1

The TPS on a 1990 is a WOT switch.

Using a multimeter set to read resistance, or a continuity tester, check the resistance between the center and bottom terminals of your TPS with engine off and throttle closed completely.

You should read continuity (or zero ohms) between those two terminals, and if you manually open the throttle slightly, the continuity should be lost (resistance goes to infinity).

A complete test takes more time; the manual states that with a 0.016" feeler gauge between the throttle lever and the throttle stop screw, you should read continuity, which should go away if you put a 0.027" gauge in there.

With the throttle fully open ("WOT"), there should be continuity between the top two terminals of the TPS. In between the idle and WOT positions, there should be no continuity between any of the terminals