Fuel Injector Test

EARLY MODEL VEHICLES
1. Ensure fuel pressure is within specifications. If pressure is not within specifications diagnose and repair any problems before proceeding with the following test. Testing and Inspection
2. If pressure is within specifications connect a tachometer and start the vehicle. Disconnect one injector wiring connector at a time and observe engine rpm. If there is no change in rpm when an injector is disconnected this injector is not operating properly.
3. Disconnect the injector wire connector from the fuel injector in question.
4. Place an ohmmeter on the fuel injector terminals. The resistance reading should be 16 ohms plus or minus 12 ohms at 20°C (68°F).
5. If there is infinite resistance, or the resistance reading is outside the listed specification, the injector is defective, and must be replaced.
6. If the resistance was within specifications connect a "noid" light to the injector connector. Turn engine over and observe the light , if the light flashes proceed to step 8.
7. If the light does not flash check for continuity between this injector connector and another injector connector in the same injector group (injectors 1,2 and 3 are grouped and injectors 4,5 and 6 are grouped). If there is no continuity in the power or the ground circuit repair the wiring and go back to step 2. If there is continuity in the power and ground circuits between the injectors inspect the suspect injector connector terminals to ensure a good connection.
8. Remove suspect injector and inspect the inlet for blockage. If the inlet is blocked replace the injector.
9 If the injector is not plugged inspect the fuel rail for restriction. Clear blockage or replace fuel rail.
10. Connect a 12 volt source to one terminal of the injector and momentarily connect a ground to the other terminal. If a distinct click is not heard when the ground is applied replace the injector.


LATE MODEL VEHICLES
1. Ensure fuel pressure is within specifications. Testing and Inspection
2. If pressure is within specifications connect a tachometer and start the vehicle. Disconnect one injector wiring connector at a time and observe engine rpm. If there is no change in rpm when an injector is disconnected this injector is not operating properly.
3. Disconnect the injector wire connector from the fuel injector in question.
4. Place an ohmmeter on the fuel injector terminals. The resistance reading should be 16 ohms plus or minus 12 ohms at 20°C (68°F).
5. If there is infinite resistance, or the resistance reading is outside the listed specification, the injector is defective, and must be replaced.
6. If the resistance was within specifications connect a "noid" light to the injector connector. Turn engine over and observe the light , if the light flashes proceed to step 8.
7. If the light does not flash check for continuity between this injectors' connector terminals and those of the other injector in the injector pair, (injector 1 is paired with 4, injector 2 is paired with 5, and injector 3 is paired with 6). If there is no continuity in the power or the ground circuit repair the wiring and go back to step 2. If there is continuity in the power and ground circuits between the injectors inspect the suspect injectors' connector terminals to ensure a good connection.
8. Remove suspect injector and inspect the inlet for blockage. If the inlet is blocked replace the injector.
9 If the injector is not plugged inspect the fuel rail for restriction. Repair or replace fuel rail.
10. Connect a 12 volt source to one terminal of the injector and momentarily connect a ground to the other terminal. If a distinct click is not heard when the ground is applied replace the injector.