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Home >> Pontiac >> 2002 >> Aztek AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel System (Diesel) >> Fuel Injector Balance Test With Tech 2 (6.6L) >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. After performing Diagnostic System Check - Engine Controls, go to next step.
  2. Are any DTCs set other than P0300, P0301-P0308? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. If no, go to next step.
    3. NOTE: Balance rates may not register when engine is off idle or engine coolant temperature is less than 126°F (52°C).
  3. Start and idle engine. Observe Balancing Rate Cyl. 1-8 parameters with scan tool. Are all Balancing Rate parameters within -4 mm3 and 4 mm3 ? If yes, go to step  5. If no, go to next step.
  4. Graph Fuel Pressure Regulator. See FUEL PRESSURE REGULATOR GRAPHING  under FUEL SYSTEM DIAGNOSIS - HIGH PRESSURE SIDE (6.6L). Is fuel pressure regulator graph normal? If yes, go to step  6. If no, go to step  8.
    5. NOTE: Fuel injector balance test must be performed under conditions for which concern occurred. Concern must be duplicated during test. DO NOT operate cruise control during this test. Cruise control reactivation after test may cause a brief extreme increase in engine speed.
  5. Observe engine speed or other customer concern. Perform Cylinder Power Balance Test in Special Functions. Do any cylinders indicate a different engine speed change than the others, or lessen customer concern? If yes, go to next step. If no, system is okay.
  6. Perform engine compression test. Do any cylinders have low compression? If yes, repair as necessary. See 6.6L V8 DIESEL article in ENGINES. If no, go to next step.
    7. NOTE: Failure to correctly identify cylinder positions may result in replacement of wrong fuel injector.
  7. Replace faulty fuel injectors on cylinders that had poor RPM drop, high balance rates, or a noise/smoke change. After repairs, go to step  9.
  8. Replace fuel pressure regulator. After repairs, go to next step.
  9. Operate vehicle under conditions in which concern occurred. Does system operate normally, with no DTCs or symptoms? If yes, system is okay. If no, go to step  2.
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