Avalanche, Sierra, Silverado, C&K Series, 1999-2005

Injection Timing

Print

The use of a suitable scan tool is required to check or adjust the injection timing.

  1. Start the engine and bring it to operating temperature.
  2.  
  3. Attach the scan tool and activate the time set. (If the time set function is activated properly the diesel injection time on the scan tool will read 0.0 degrees.
    NOTE
    The actual injection time on the scan tool will fluctuate. The average reading should be 3.5 degrees.

  4.  
  5. Read the actual injection time using the scan tool functions. The reading should be 3.5 degrees.
    NOTE
    If the engine stalls during time set activation, slightly rotate the injection pump (1mm = 2degrees) towards the drivers side of the vehicle, tighten the flange nuts and repeat time set.

  6.  
  7. If the injection timing is correct, the adjustment is complete. If the timing is incorrect continue with the procedure.
  8.  
  9. On some models it may be necessary to move the A/C compressor to the side to improve access to the injection pump lower mounting bolts.
  10.  
  11. With the engine OFF , loosen the pump flange nuts.
  12.  
  13. Slightly rotate the injection pump in the desired direction (towards the drivers or passenger side of the vehicle) until the set injection time is 3.5 degrees.
    NOTE
    It is normal for the actual injection time shown on the scan tool screen to fluctuate. Average fluctuation should be 3.5 degrees.

  14.  
  15. Tighten the pump bolts.
  16.  
  17. If moved, install the A/C compressor and remove the scan tool.
  18.  
  19. Road test the vehicle.
  20.  

On Diesel engines, the injection timing is controlled by the Powertrain Control Module (PCM). No adjustment is necessary or possible.

On the 6.6L engine the Engine Control Module (ECM) controls the fuel injection timing, no further adjustment is possible.

Tools Required: J 41089 Injection Pump Wrench; J 29872-A Injection Pump Adjustment Tool

This procedure should be used after an injection pump installation or when injection timing needs to be checked or adjusted. A scan tool must be used to check or adjust injection timing. A static timing mark can be used as a reference. If a static timing mark is not present on the injection pump mounting flange, one can be scribed to further assist in how far the injection pump needs to be rotated.

Injection Pump Timing Specification: 3.5 degrees.


NOTE
There will be no change in engine performance or vehicle driveability if injection timing is advanced during the Time Set procedure. Injection timing must be set to Injection Timing Specifications. If injection timing is not set correctly, a possible DTC P0216 may set (see DTC P0216, Conditions for setting the DTC).

  1. Start the engine.
  2.  
  3. Run the engine to operating temperature.
  4.  
  5. Install a scan tool.
  6.  
  7. Use a scan tool to activate Time Set (if Time Set has been activated correctly, Des. Inj. Time on the scan tool will read 0.0 degrees).
    NOTE
    The Act. Inj. Time value on the scan tool will fluctuate. The average reading should be 3.5 degrees.

  8.  
  9. Act. Inj. Time (scan tool display) should be approximately 3.5 degrees. If not, continue to step 6.
    NOTE
    If engine stalls during Time Set activation, slightly (1mm equals 2 degrees) rotate the injection pump toward the driver side of the vehicle, tighten flange nuts and repeat Time Set.

  10.  
  11. If the injection timing needs to be adjusted, continue. If not, adjustment is complete.
    NOTE
    Move the A/C compressor to the side to improve access to the injection pump lower mounting bolts.

  12.  
  13. Turn the engine OFF and loosen the injection pump flange nuts using tool J 41089 injection pump wrench.
  14.  
  15. Slightly rotate the injection pump using tool J 29872-A injection pump adjustment tool.
  16.  
  17. Set Act. Inj. Time to 3.5 degrees.
    NOTE
    It is normal for the Act. Inj. Time value on the scan tool to fluctuate. The average fluctuation of Act. Inj. Time should be 3.5 degrees.

  18.  
  19. Continue to repeat the procedure until average fluctuation of Act. Inj. time is 3.5 degrees. If the Act. Inj Time is above 3.5 degrees SLIGHTLY (1 mm equals 2 degrees) rotate injection pump towards the passenger side of vehicle. If the Act. Inj time is below 3.5 degrees, SLIGHTLY (1 mm equals 2 degrees) rotate injection pump toward drivers side of vehicle.
  20.  

On diesel engines the idle speed and injection timing is controlled by the Powertrain Control Module (PCM). There is no provision for adjustment.

On the 6.6L engine, the Powertrain Control Module (PCM) controls the fuel injection timing, no further adjustment is possible.

On diesel engines the idle speed and injection timing is controlled by the Powertrain Control Module (PCM). There is no provision for adjustment.

On the 6.6L engine, the Powertrain Control Module (PCM) controls the fuel injection timing, no further adjustment is possible.

6.5L Engine



The use of a suitable scan tool is required to check or adjust the injection timing.

  1. Start the engine and bring it to operating temperature.
  2.  
  3. Attach the scan tool and activate the time set. (If the time set function is activated properly the diesel injection time on the scan tool will read 0.0 degrees.
    NOTE
    The actual injection time on the scan tool will fluctuate. The average reading should be 3.5 degrees.

  4.  
  5. Read the actual injection time using the scan tool functions. The reading should be 3.5 degrees.
    NOTE
    If the engine stalls during time set activation, slightly rotate the injection pump (1mm = 2degrees) towards the drivers side of the vehicle, tighten the flange nuts and repeat time set.

  6.  
  7. If the injection timing is correct, the adjustment is complete. If the timing is incorrect continue with the procedure.
  8.  
  9. On some models it may be necessary to move the A/C compressor to the side to improve access to the injection pump lower mounting bolts.
  10.  
  11. With the engine OFF , loosen the pump flange nuts.
  12.  
  13. Slightly rotate the injection pump in the desired direction (towards the drivers or passenger side of the vehicle) until the set injection time is 3.5 degrees.
    NOTE
    It is normal for the actual injection time shown on the scan tool screen to fluctuate. Average fluctuation should be 3.5 degrees.

  14.  
  15. Tighten the pump bolts.
  16.  
  17. If moved, install the A/C compressor and remove the scan tool.
  18.  
  19. Road test the vehicle.
  20.  

 
label.common.footer.alt.autozoneLogo