Fuel Injector Balance Test
- If powertrain OBD system check been performed, go to next step. If powertrain OBD system check has not been performed, perform powertrain OBD system check. See POWERTRAIN OBD SYSTEM CHECK in TESTS W/CODES article.
- If fuel injector coil test has been performed, go to next step. If fuel injector coil test has not been performed, perform appropriate fuel injector coil test. See FUEL INJECTOR COIL TEST - ECT BETWEEN 50-95°F or FUEL INJECTOR COIL TEST - ECT NOT BETWEEN 50-95°F.
- If engine coolant temperature greater than 201°F (94°C), go to next step. If engine coolant temperature less than 201°F (94°C), go tostep 5).
- Allow engine to cool to less than 201°F (94°C) and go to next step.
- Install fuel pressure gauge. Turn ignition switch to RUN position, then to LOCK position. Bleed air from fuel pressure gauge. Turn ignition switch to RUN position then to LOCK position. If fuel pressure reading is 36-43 psi, go to next step. If fuel pressure reading is not 36-43 psi, repair fuel system as necessary.
- Observe fuel pressure gauge with ignition switch in LOCK position. If fuel pressure remains constant, go to next step. If fuel system does not remain constant, repair fuel system.NOTE: Perform step 7) on each injector.
- Disconnect fuel injectors harness connector. Using Fuel Injector Adapter (J-34730-3A), connect Fuel Injector Tester (9J-39021) to fuel injector. Connect fuel injector tester power leads to appropriate battery terminals. Set amperage supply selector switch on fuel injector tester to Balance Test 0.5-2.5 amp position. Turn ignition switch to RUN position, then to LOCK position. Record fuel pressure reading (first reading). Energize injector by depressing PUSH TO START TEST button on injector tester and hold until fuel pressure gauge stabilizes. Record fuel pressure reading (second reading). Subtract first reading from second reading (this result is pressure drop value). Add pressure drop value for each injector together and divide total by 4. If any injector's drop value is greater or less than average drop value by 1.5 psi, replace faulty injector(s) as necessary. If no injector's drop value is greater or less than average drop value by 1.5 psi, injector balance test is okay at this time.
WARNING:
In order to prevent flooding of cylinder and possible engine damage, relieve fuel pressure before performing injector coil test procedure.