GM/Detroit 6.5L ENGINE CONTROLS – Injection Timing Adjustment

Tools Required
• J 41089 Injection Pump Wrench
• J29872-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
All injection pump timing averages 3.5 degrees.

Important: 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. Run the engine to operating temperature.
3. Install a scan tool.
4. 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).

Important: The Act. Inj. Time value on the scan tool will fluctuate. The average reading should be
3.5 degrees.
5. Act. Inj. Time (scan tool display) should be approximately 3.5 degrees. If not, continue to step 6.
Important: If engine stalls during Time Set activation, slightly (1 mm equals 2 degrees) rotate the injection pump toward the driver side of the vehicle, tighten flange nuts and repeat Time Set.
6. If the injection timing needs to be adjusted, continue. If not, adjustment is complete.

Important: Move the A/C compressor to the side to improve access to the injection pump lower mounting bolts.
7. Turn the engine OFF and loosen the injection pump flange nuts using the J 41089 injection pump wrench.
8. Slightly rotate the injection pump using the J 29872-A injection pump adjustment tool.
9. Set Act. Inj. Time to 3.5 degrees.

Important: 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.
10. 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.


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