A/T Vacuum Regulator Valve - Adjustment Procedure

Article No. 85-11-20

TRANSMISSION - AUTOMATIC - C6 - 6.9L (D) ENGINE - VACUUM REGULATOR VALVE (VRV) - REVISED ADJUSTMENT PROCEDURE

LIGHT TRUCK 1983-85 E & F SERIES

To assure VRV adjustment accuracy, Steps 3, 6, and 10 of the VRV Operational Check and Adjustment Procedure on page 17-10-4 of the 1985 Truck Shop Manual (Volume 4) have been changed. The principle change in the procedure is:

^ Cycle the throttle lever 5 times from idle to wideopen throttle with 20 inches of vacuum applied, prior to making adjustments as noted in Steps 6 and 10 of the following complete procedure.

Figure 30 VACUUM REGULATOR VALVE (VRV) - E-250 - E-350, F-250 - F-350 WITH 6.9L DIESEL ENGINE:

VACUUM REGULATOR VALVE (VRV) OPERATIONAL CHECK AND ADJUSTMENT

Refer to Figure 30.
To check the VRV for proper operation and to adjust, the engine must not be running (MUST BE TURNED OFF).

1. Disconnect the two port vacuum connector from the VRV located on the left side of the fuel injection pump.

2. Remove the throttle cable from the throttle lever on the right side of the fuel injection pump.

3. Remove the throttle return spring. Install the end of the spring over the throttle lever ball stud and the other end over the throttle cable support bracket.

4. Attach a vacuum pump to the upper port of the VRV (vacuum supply side).

5. Attach a vacuum gauge to the lower port of the VRV, labeled TRANS on the VRV.

Figure 31 - VRV GAUGE BLOCK INSTALLATION:

6. Apply 20 inches of vacuum to the VRV and maintain. It will be necessary to pump the vacuum up as it bleeds off. Cycle the throttle lever 5 times from idle to wide-open throttle with vacuum applied, Insert the gauge block, T83T-7B200-AH (0.515 inch), between the pump boss and the throttle wide-open stop (Figure 31). The throttle return spring, as repositioned in Step 3 above, will hold the throttle lever stop against the gauge block. The vacuum gauge attached to the lower port of the VRV should indicate 6-8 inches of vacuum. If the vacuum reading is not correct, adjust the VRV to achieve a reading of 7 inches of vacuum.

Figure 30 VACUUM REGULATOR VALVE (VRV) - E-250 - E-350, F-250 - F-350 WITH 6.9L DIESEL ENGINE:

7. To adjust, loosen the two adjustment screws that attach the VRV to the fuel injection pump (Figure 30). Rotate the VRV until the proper vacuum is obtained. Tighten the two adjusting screws to 8- 10.5 Nm (75-90 in.lbs.) when the proper vacuum reading is obtained. If the VRV cannot be adjusted to obtain the proper vacuum, replace the VRV and repeat procedure in Step 3.
8. Remove the gauge block.

9. Reattach the throttle return spring and throttle cable.

10. Again, apply 20 inches of vacuum to the VRV and while maintaining vacuum, cycle the throttle lever from idle to wide-open throttle 5 times. The vacuum gauge must indicate at least 13 inches (throttle at idle position). If vacuum gauge indicates less than 13 inches, the VRV must be replaced and the new VRV adjusted per the above procedures.

11. After making the check or adjustment, remove the vacuum pump and gauge from the VRV and reattach the vacuum connector.

12. Start engine and check throttle operation and check transmission shifts.

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY"