CTS-V V8-6.0L VIN U (2006)
6. Perform the Fuel Injector Balance Test with Special Tool or the Fuel Injector Balance Test with Tech 2.
Fuel Injector Balance Test with Special Tool
1. Set the amperage supply selector switch on the fuel injector tester to the Balance Test 0.5-2.5 amp position.
2. Connect the J 39021 to a fuel injector with a J 44602.
3. Command the fuel pump relay ON and then OFF with a scan tool.
4. Record the fuel pressure indicated by the fuel pressure gage after the fuel pressure stabilizes. This is the first pressure reading.
5. Energize the fuel injector by depressing the Push to Start Test button on the fuel injector tester.
IMPORTANT: The fuel pressure may rise after the fuel injector stops pulsing. Record the fuel pressure value immediately after the fuel injector
stops pulsing. DO NOT record the higher fuel pressure value.
6. Record the fuel pressure indicated by the fuel pressure gage after the fuel injector has stopped pulsing. This is the second pressure reading.
7. Repeat steps 2-6 for each fuel injector.
8. Perform the Pressure Drop Calculation.
Fuel Injector Balance Test with Tech 2
1. With a scan tool, select the Fuel Injector Balance Test function within the Special Functions menu.
2. Select an injector to be tested.
3. Press Enter to prime the fuel system.
4. Record the fuel pressure indicated by the fuel pressure gage after the fuel pressure stabilizes. This is the first pressure reading.
5. Energize the fuel injector by depressing the Pulse Injector button on the scan tool. This will energize the injector and decrease the fuel pressure.
IMPORTANT: Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector
stops pulsing. DO NOT record the higher fuel pressure value.
6. Record the fuel pressure indicated by the fuel pressure gage after the fuel injector has stopped pulsing. This is the second pressure reading.
7. Press Enter again to bring you back to the Select Injector screen.
8. Repeat steps 2-7 for each fuel injector.
9. Perform the Pressure Drop Calculation.
Pressure Drop Calculation
1. Subtract the second pressure reading from the first pressure reading for one fuel injector. The result is the pressure drop value.
2. Obtain a pressure drop value for each fuel injector.
3. Add all of the individual pressure drop values. This is the total pressure drop.
4. Divide the total pressure drop by the number of fuel injectors. This is the average pressure drop. The difference between any individual pressure
drop and the average pressure drop should not be more than 20 kPa (3 psi).
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If the difference between any individual pressure drop and the average pressure drop is more than 20 kPa (3 psi), replace the fuel injector.
REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Computers and Control Systems/Testing and
Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests and Procedures
Fuel Injector and Fuel Rail Replacement
