Envoy 2WD L6-4.2L (2008)
10. Repeat steps 3 through 9 for each fuel injector.
11. Perform the Pressure Drop Calculation.
Pressure Drop Calculation
1. Subtract the minimum pressure from the starting pressure 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 except for the injector suspected of being faulty. This is the total pressure drop.
4. Divide the total pressure drop by the number of fuel injectors that were added together. 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(s).
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 Replacement