Diesel MFI Pump: Adjustments

Timing Rotation:

CHECKING OR ADJUSTING INJECTION TIMING
A TECH 1- scan tool must be used to check or adjust injection timing. Original factory timing is marked with a static timing mark, which is a line scribed across both the pump mounting flange and the front cover. This static timing mark can be used as a reference. If the 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.

1. Start and idle engine until warm.
2. Install Tech 1 scan tool.
3. Activate "TDC TIME SET" in the "OUTPUT TEST/INJ PUMP" section of the tech 1 scan tool. Refer to Tech 1 scan tool for proper way to activate "OUTPUT TEST." When "TDC TIME SET" is activated "DESIRED INJ TIM" value in TECH 1 will read 0.

NOTE: If engine stalls during "TDC TIME SET" activation, slightly rotate injection pump toward the driver side of the vehicle, tighten mounting nuts and repeat Step 3.

4. Observe "MEASURED INJ TIM" for proper timing specification. If a change is necessary, shutdown engine and loosen injection pump mounting nuts. With J 29872 slightly rotate injection pump (1mm=2°).

CAUTION: While "MEASURED INJ TIM" can only be observed while engine is running, engine must be shutdown while injection pump is being adjusted to prevent engine damage.

5. Restart engine and observe "MEASURED INJ TIM" value on TECH 1 scan tool. If it is necessary to re-adjust injection timing, repeat Step 3 and 4 until correct injection timing is achieved.

NOTE: "MEASURED - INJ TIM" value will fluctuate slightly while Powertrain Control Module (PCM) is in set timing mode.

Tighten
- Pump retaining nuts to 40 Nm (30 lb. ft.).

BACKUP TIMING PROCEDURE
This procedure should only be used when one of the following conditions exists.

1. The front cover and PCM have been removed and replaced at the same time.
2. The pump and PCM have been removed and replaced at the same time.
3. The front cover and/or crank sensor, pump and PCM have been removed and replaced at the same time.
4. The front cover has been removed.
5. A complete engine is replaced.

This procedure uses the TDC offset learn procedure to provide correct "Injection Pump Timing Proceed" as follows:

1. Start and idle engine until warm.
2. Install Tech 1 scan tool.
3. Activate "TDC OFFSET LEARN" in "OUTPUT - TEST"/"INJ PUMP" section of Tech 1 scan tool.

NOTE: If engine stalls during TDC offset activation, slightly rotate pump toward the driver side of the vehicle and tighten mounting nuts and repeat step 3.

4. If the learned "TDC OFFSET" is between 0.00 and -0.50°, procedure is complete; if not, slightly rotate pump and retighten mounting nuts. Repeat steps 3 and 4 until "TDC OFFSET" value is between 0.00 and -0.50°.


NOTE: To achieve a negative (-) number, rotate pump toward driver side; a positive (+) number, rotate toward passenger side. 1mm pump movement = approximately 2°.