Fuel Injector Balance Test

NOTE: Make sure injectors have been cleaned with an approved cleaner prior to testing. Fuel Injector Cleaning Procedure
The injector balance test is done to verify a balanced distribution of fuel to all cylinders.
1. Start by hooking up a fuel presure gauge inline before the fuel pressure regulator (refer to gauge manufacturer instructions).
2. Pressurize the fuel rail by turning ignition to the ON position, and energizing the fuel pump. Fuel pressure should rise to maximum working pressure. Fuel Pressure
3. Remove injector harness connector and connect an injector pulse tester.
4. Pulse one injector at a time. Allow pressure to rise and stabilize in between each injector tested.
NOTE: The time each injector is pulsed is very important. Each injector should be pulsed at the same time interval (example 1 ms each).
5. The rate of drop should be even across all the injectors. All injector pressure drops should be within 3% of each other, if an injector pressure drop differs from the others by more than 3% replace the injector.
6. If there is no pressure drop when the injector is pulsed, verify there is a good connection between the injector and pulse tester. If connection is good, a check of the injector circuit is required.
7. First, check the resistance of the injector. [1][2]Fuel Injector Test
8. If resistance is OK verify there is power to injector by reconnecting the injector harness connector and START engine.
9. Use a "NOID" light to check for pulses (light off and on). If it does not light this is an indication of a problem in the injector to ECU circuit. Fuel Injector Electrical Circuit Diagnosis
NOTE: It may not be possible to connect a noid light to the harness while connected to the injector. If this is the case disconnect the harness and connect the noid light to the harness and check pulses.
10. If light pulses, recheck pressure drop to verify malfunction.