Fuel Injectors Test
- Check system fuel pressure. Fuel pressure should be between 28-30 psi (1.97-2.11 kg/cm2 ). Repair fuel system if fuel pressure is not within specification.
- If fuel pressure is within specification, start vehicle and disconnect fuel injector electrical connector one at a time while observing engine RPM. Engine RPM will not change if fuel injector is not operating.
- Using an ohmmeter, measure resistance between fuel injector terminals. Ohmmeter should read approximately 2.4 ohms resistance at 68°F (20°C). Replace fuel injector if resistance is not within specification.
- If resistance is within specification, connect a 12-volt test light across injector connector terminals (wire harness side). Observe test light while cranking engine.
- If test light flashes on and off, go to step 6). If test light does not flash on and off, check injector power and ground circuits. Repair as required. If circuits are okay, test vehicle with Diagnostic Readout Box (DRB-II) and Jeep/Eagle adapter or similar scan tool. See appropriate G - TESTING W/CODES article.
- If test light flashed on and off in step 4), remove fuel injector from fuel rail and intake manifold. Inspect injector inlet for blockage. If injector inlet is plugged, replace injector. If inlet is not plugged, go to next step.
- Inspect fuel supply line and fuel rail for blockage. Repair as required. If blockage is not found, go to next step.
- Connect a 12-volt source to one injector terminal. Repeatedly connect and disconnect a ground source to other terminal. Injector should click each time ground is supplied. Replace injector if it does not click when ground is supplied.