Diagnostic Aids

Fuel spray may exist at fuel injector, but may not be enough to start engine. If both fuel injector and circuit are okay, fuel injector nozzle may be partly blocked.

Also check the following for a possible cause of fault:

• Check fuel injector resistor connections and resistance. Resistor resistance should be 1.9-2.8 ohms at 68°F (20°C).
• An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation or a wire broken inside insulation. Check for an open or loose or disconnected terminals.

1. Turn ignition off. Disconnect fuel injector connector. Install fuel injection test light (noid-light J-34730-2B) into injector harness connector. Crank engine. If noid-light flashes, go to next step. If noid-light does not flash, go to step 4).
2. Using an ohmmeter, measure resistance of fuel injector. If resistance is 0.5-1.5 ohms at 68°F (20°C), go to next step. If resistance is not as specified, replace fuel injector. Ensure system is operating properly.
3. Check for restrictions or partly blocked fuel injector nozzle. If fuel injector is okay, go to TEST A1-7A  under CIRCUIT TESTS. Repair as necessary. Ensure system is operating properly.
4. If noid-light does not illuminate, go to next step. If noid-light remains illuminated while engine is cranking, check for short to ground in Yellow/Black wire between fuel injector and PCM. See appropriate wiring diagram in the WIRING DIAGRAMS article. Repair as necessary. If wire is okay, replace PCM. Ensure system is operating properly.
5. Remove noid-light. Turn ignition on. Using a voltmeter, measure voltage between ground and fuel injector harness connector terminal No. 1 (Yellow wire). If battery voltage is present, go to next step. If battery voltage is not present, go to step 7).
6. Connect a test light between battery voltage and fuel injector harness connector terminal No. 2 (Yellow/Black wire). Crank engine. If test light flashes while cranking engine, ensure connection at fuel injector is okay. If connection is okay, replace fuel injector. If test light does not flash, check for an open in Yellow/Black wire. If wire is okay, replace PCM. Ensure system is operating properly.
7. Turn ignition on. Using a voltmeter, backprobe between fuel injector resistor connector terminal No. 1 (White/Blue wire) and ground. If battery voltage is present, go to next step. If battery voltage is not present, check for open in White/Blue wire between main relay and fuel injector resistor. Repair as necessary. Ensure system is operating properly.
8. Check for open or short to ground in Yellow wire between fuel injector resistor and fuel injector. Repair as necessary. If wire is okay, replace fuel injector resistor. Ensure system is operating properly.