The following information for testing the synch sensor is from the FSM 97:
"For this test, an analog (non-digital) voltmeter is needed. Do not remove the distributor connector from the distributor. Using small paper clips, insert them into the backside of the distributor wire harness connector to make contact with the terminals. Be sure that the connector is not damaged when inserting the paper clips. Attach voltmeter leads to these paper clips.
(1) Connect the positive (+) voltmeter lead into the sensor output wire. This is at done the distributor wire harness connector.
(2) Connect the negative (-) voltmeter lead into the ground wire.
(3) Set the voltmeter to the 15 Volt DC scale.
(4) Remove distributor cap from distributor (two
screws). Rotate (crank) the engine until the distributor rotor is approximately in the 11 o’clock position. The movable pulse ring should now be within the sensor pickup.
(5) Turn ignition key to ON position. Voltmeter
should read approximately 5.0 volts.
(6) If voltage is not present, check the voltmeter leads for a good connection.
(7) If voltage is still not present, check for voltage at the supply wire.
(8) If 5 volts is not present at supply wire, check
for voltage at PCM 32-way connector (cavity A-17). Leave the PCM connector connected for
this test.
(9) If voltage is still not present, perform vehicle
test using the DRB scan tool.
(10) If voltage is present at cavity A-17, but not at the supply wire:
(a) Check continuity between the supply wire.
This is checked between the distributor connector and cavity A-17 at the PCM. If continuity is not present, repair the harness as necessary.
(b) Check for continuity between the camshaft
position sensor output wire and cavity A-18 at the PCM. If continuity is not present, repair the harness as necessary.
(c) Check for continuity between the ground circuit wire at the distributor connector and ground. If continuity is not present, repair the harness as necessary.
(11) While observing the voltmeter, crank the
engine with ignition switch. The voltmeter needle should fluctuate between 0 and 5 volts while the engine is cranking. This verifies that the camshaft position sensor in the distributor is operating properly and a sync pulse signal is being generated. If sync pulse signal is not present, replacement of the camshaft position sensor is necessary."