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Intermittent Extended Crank During Hoat Soak Restart - keywords debris dust fuel hard injectors inlet long module no pump repeat start

Subject:Intermittent Extended Crank During Hot Soak Restart

Models:2007-2008 Cadillac Escalade
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007-2008 GMC Sierra, Yukon
with 5.3L E85 Engine (RPO LC9 or LMG)



The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Some customers may complain of an intermittent extended crank when restarting their engine after a hot soak (typically 30-60 minutes). This may be the result of a fuel injector or fuel pump concern. Typically, no DTCs will be stored upon inspection and if this is related to a fuel injector concern, the technician may notice that the engine starts quicker if they press the accelerator pedal.

Recommendation/Instructions:

If this complaint is encountered, perform the Hard Start Diagnosis in SI and repair as necessary. The Hard Start Diagnosis will also link to the Fuel System Diagnosis and Fuel Injector Diagnosis in SI. Typically, one of these procedures will isolate a fuel injector or fuel pump concern if the fuel pressure is obviously low, slow to build, or bleeds down quickly after the fuel pump stops running.

If the procedures above do not isolate a cause for this concern because the fuel pressure is not obviously low, is not slow to build, and does not bleed down quickly after the fuel pump stops running, perform the following suggestions:

  1. Allow the engine to run until operating temperature is achieved and turn off the engine.
  2. As a safety precaution, disable the fuel injectors and ignition coils by pulling the INJ-A and INJ-B fuses in the UBEC.
  3. Follow SI procedures to lift up the fuel rail, leaving the fuel feed line connected and all fuel injectors installed.
  4. Place card board or a shop towel under all fuel injector tips.
  5. Use the Tech 2 to pressurize the fuel system while in the KOEO position.
  6. Close the hood and allow the engine to hot soak for the period of time described by the customer (typically 30-60 minutes).
  7. Open the hood and inspect the tips of all fuel injectors for drips.
  8. • If only one fuel injector drips, replace just that fuel injector and re-evaluate the concern. Cleaning the fuel injectors will not correct this fuel injector concern.
    • If two or more fuel injectors drip, replace all eight fuel injectors and the fuel tank fuel pump module, contact Ashmi Haria at 586-492-5418 so she can arrange to get the parts back for engineering inspection, and re-evaluate the concern. Please use a paint pen to mark the body of any dripping fuel injector to identify it as a dripping fuel injector for engineering. Cleaning the fuel injectors will not correct this fuel injector concern.
  9. Follow SI procedures to reassemble the engine, install the INJ-A and INJ-B fuses, and clear any DTCs that may have set as a result of having the fuses removed.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.