The cam position sensor is located inside your distributor with a plug in harness coming out. You'll want to disconnect your coil electrical connector, and remove your fuel pump relay from your pdc. Unplug the connector and you'll want to test the signal from your pcm first. Connect the positive lead of the voltmeter to the white/black wire terminal and the negative to the black/light blue wire terminal of the connector. Then turn the key on, the voltage should read approx. 8.0 volts for a pre- 95. If its not you'll want to check your wiring from the connector to the pcm. If it reads ok then check the cam pos sensor by reconnecting it and backprobing the gray/black wire terminal of the cam pos sensor with the positive probe and put the negative on a good engine ground point. Then have someone crank yhe engine over, the voltage should fluctuate from around 5.0 volts to 0.0. Any other reading and its time to replace it.