Cam pos. sensor could be bad, it is in the distributor. Make sure that the distributor is still turning and something didn't break, maybe replace it with a junkyard one anyways.
Check ignition module.
The Camshaft Position (CMP) Sensor is located in the distributor housing under the ignition rotor and pulse ring
The signal from the Camshaft Position (CMP) Sensor combined with the input signal from the Crankshaft Position (CKP) Sensor, are what the Powertrain Control
Module (PCM) uses to properly synchronize fuel injection.
The CMP Sensor is used to reference firing cylinders, it sends voltage to the PCM and works
in conjunction with the CKP sensor so that the PCM can establish and maintain the correct injector firing order.
The camshaft position sensor uses a 180°pulse ring on the end of the distributor shaft. The leading edge of the 180°pulse ring indicates that number 1 cylinder is nearing Top Dead Center (TDC). The trailing edge of the pulse ring indicates that the number 6 cylinder is nearing TDC.
The CMP sensor generates a high/low voltage signal, as the pulse ring passes a hall effect switch. When the pulse ring passes in front of the hall effect switch, a 5 volt signal is sent to the PCM. When a slot is not present, the PCM receives a 0.3 volt signal.
If PCM does not sense input from cam position sensor
, PCM will deactivate ASD and fuel pump
relays, interrupting voltage to fuel pump, fuel injectors, and ignition coil
, causing a no start condition.
NOTE: For this test, an analog (non-digital) voltmeter is needed. Do not remove the distributor connector from the distributor. To perform a complete test of the Camshaft Position Sensor and its circuitry, refer to the DRB II diagnostic tester. Also see the appropriate Diagnostic Charts. To test the sensor only, refer to the following:
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.
- Connect the positive (+) voltmeter lead into the sensor output wire. This is done at the distributor wire harness connector.
- Connect the negative (-) voltmeter lead into the ground wire.
- Set the voltmeter to the 15 Volt DC scale.
- Remove distributor cap from distributor (two screws). Rotate (crank) the engine until the distributor rotor is pointed towards the rear of vehicle. The movable pulse ring should now be within the sensor pickup.
- Turn ignition key to ON position. Voltmeter should read approximately 5.0 volts.
- If voltage is not present, check the voltmeter leads for a good connection.
- If voltage is still not present, check for voltage at the supply wire.
- If voltage is not present at supply wire, check for voltage at pin-7 of Powertrain Control Module (PCM) 60-way connector. Leave the PCM connector connected for this test.
- If voltage is still not present, perform vehicle test using the DRB II diagnostic scan tool.
- If voltage is present at pin-7, but not at the supply wire:
- Check continuity between the supply wire. This is checked between the distributor connector and pin-7 at the PCM. If continuity is not present, repair the harness as necessary.
- Check for continuity between the Camshaft Position Sensor output wire and pin-44 at the PCM. If continuity is not present, repair the harness as necessary.
- Check for continuity between the ground circuit wire at the distributor connector and ground. If continuity is not present, repair the harness as necessary.
- 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.