CTS RWD V6-3.6L (2008)
‹› If the fuel pressure is not within the specified range refer to Fuel System Diagnosis (See: Computers and Control Systems/Testing and
Inspection/Component Tests and General Diagnostics) for further diagnosis of the fuel system.
4. Monitor the fuel pressure gage for 1 minute. Verify that the fuel pressure does not drop more than 34 kPa (5 psi).
‹› If the fuel pressure decreases more than 34 kPa (5 psi) refer to Fuel System Diagnosis (See: Computers and Control Systems/Testing and
Inspection/Component Tests and General Diagnostics) for further diagnosis of the fuel system.
Notice: Do Not repeat any portion of this test before running the engine in order to prevent the engine from flooding.
5. Connect the J 39021 , J 39021-210 , and EL-39021-460 to the muti-way connector of the fuel injectors, with the amperage supply selector switch
set to the 0.5-2.5 amp position. If the upper intake manifold has been removed, use J 44602 in place of J 39021-210 and EL-39021-460 , and
connect directly to a fuel injector.
6. Command the fuel pump relay ON with a scan tool and record the fuel pressure indicated by the fuel pressure gage after the fuel pressure
stabilizes. This is the first pressure reading.
Important:
*
Repeat this step for each fuel injector in order to obtain a pressure drop value for each fuel injector.
*
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.
7. Energize the fuel injector by depressing the Push to Start Test button on the fuel injector tester. Record the fuel pressure indicated by the fuel
pressure gage after the fuel injector has stopped pulsing. This is the second pressure reading.
8. Add all of the individual pressure drop values in order to calculate the total pressure drop. Divide the total pressure drop by the number of fuel
injectors in order to calculate 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).
‹› 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 (See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Tests and
Associated Procedures/Verification Tests and Procedures) after completing the diagnostic procedure.
Fuel Injector and Fuel Rail Replacement (LP1, LY7) (See: Service and Repair/Fuel Injector and Fuel Rail Replacement (LY7) VIN 7 W/O Direct Fuel
Injection)
