Usage:
Introduction
NOTE: Some photographs and illustrations in this book are of the DB2 Fuel Pump. The DB4 Fuel Pump is slightly different, but the procedures given are basically the same.
DB2 Fuel Pump
DB4 Fuel Pump
This section provides the setup and adjustment procedures for testing and adjusting Fuel Injection Pumps. The fuel injection pumps are tested using the Fuel Injection Equipment Test Stand. See Special Instruction SEHS8200, "Using the Fuel Injection Equipment Test Stand:" for operating instructions.
These pumps can also be tested on earlier fuel injection test benches using the same tooling and procedures. See Special Instruction SEHS7465.
Fuel Injection Pump
Tooling
The tools listed are required to test the pump and governor assembly. These tools are not available in a group and must be purchased separately.
Mounting Tools
Calibration Fluid and Lube Line Tooling
Pump
Mount Pump To Test Stand
Base Plate Attached To Rails Of Test Stand
1. Attach 6V9132 Base Plate (1) to test stand rails using 6V9138 Mounting Assembly (T-Bar) and 6V9134 Lock Screw (2).
2. Attach 1U5366 Pump Mounting Plate (3) to base plate using four 0T0924 Bolts and 5M2894 Flat Washers.
Pump Mounted To Pump Mounting Plate
Connect Pump Drive Adapters To Test Bench
Pump Adapter
1. Install 9U7493 Drive Adapter (1) with 118-1713 Flat Washer and 118-1711 Nut (2). Tighten nut (2) to 55 N·m (40 lb ft).
Drive Adapter
Drive Adapter
3. Align keyway and connect the drive adapter to the chuck. Insert shaft approximately one inch into chuck.
4. Tighten two bolts in chuck.
a. Tighten lock screw on base plate.
b. Install guards.
Testing Pump
NOTE: If the pump is equipped with an aneroid, the aneroid rod must be disconnected before the pump is run on the test stand.
Timing Cover
1. Remove timing cover (1).
Timing Indicator Assembly
2. Attach 4C8126 Timing Indicator Assembly (2).
Pressure Tap Screw
3. Remove pressure tap screw (3) and lock (8) from the transfer pump.
4C8054 Tap Fitting Assembled
4. Install reducer (6) in 4C8054 Tap Fitting (7). Install shutoff valve (5) on reducer (6). Install fitting (4) to shutoff valve (5).
Assembled 4C8054 Tap Fitting Installed
5. Put lock (8) on 4C8054 Tap Fitting (7). Install the assembled 4C8054 Tap Fitting (7) to check transfer pump pressure.
Line Connected To Transfer Pump Fittings
6. Connect hose (9) from the 1400 kPa auxiliary gauge to the transfer pump fittings.
Fuel Injector Test Tube Assemblies
7. Connect 127-4365 Fuel Injection Test Tube Assemblies (10). Assemble from front of fuel pump to manifold block and tighten.
Fuel Inlet Connected To Test Bench
8. Connect hose (11) to test bench.
Fuel Return Connected To Test Bench
9. Connect hose (13) to test bench.
Pressure Line Connected To Timing Indicator Assembly
10. Connect housing pressure line (16) from the 700 kPa auxiliary gauge to 4C8126 Timing Indicator Assembly (2).
Shutoff Device Connected
11. Connect cables (19) to terminals (18).
NOTE: This connects the energized-to-run shutoff device to the test bench. Polarity does not matter.
12. Be sure the 12/24 volt switch on back of the test bench is set to 12 volts and the circuit trip switch is in the "ON" position.
13. Be sure the lube oil switch is turned to the "OFF" position.
NOTE: Lube oil is not used with this pump.
14. Turn test switch "ON" and adjust pressure to specified pressure.
15. Adjust test oil temperature to 45 ± 2°C.
16. Be sure the test bench drives the pump in the specified direction.
Spring Connected to Throttle
17. Put one end of spring (20) on the throttle and hook the other end on a 127-4365 Fuel Line Assembly (10).
18. Operate the pump for 10 minutes at 500 rpm with the throttle in the completely open position. This procedure will bring the system to operating temperature and remove air from the system.
NOTE: If the pump has not been adjusted or disassembled, check the pump with the correct specifications from TMI. If the pump is within specifications, no adjustment is required. If the pump has been adjusted or disassembled go to the next step.
19. (If equipped) disconnect the aneroid.
20. On Electric Power Generator Engine Pumps, turn the speed droop to minimum position (counterclockwise direction). Reset the idle screw per TMI.
Idle adjustment Screws And Torque Screw
NOTE: On Electric Power Generator Engine Pumps, do not back out low idle screw (21).
21. Back out low idle screw (21), high idle screw (22), and torque screw (23), and aneroid rear screw (if equipped).. Make sure the screws do not interfere with the following tests.
22. Check fuel shutoff device per specifications.
23. Check transfer pump lift:
a. Turn fuel pressure OFF at test bench and check to be sure that the bench gauge indicates the vacuum specified in TMI for this pump.
b. Turn bench fuel pressure ON as soon as specified vacuum is achieved.
24. Set transfer pump pressure by stopping the test bench, remove fuel inlet (11).
Fuel Inlet Line Removed
Setting Transfer Pump Pressure
25. To adjust pressure, turn internal adjusting screw with 4C6827 Hex Bit Driver (24). Clockwise adjustment increases the pressure. Counterclockwise adjustment decreases the pressure. Repeat this step until the pressure is set correctly.
26. Close the transfer pump outlet line shutoff valve.
27. Check return test oil flow.
a. Stop the test bench and connect pump return port to metered return port on test bench.
b. Run pump at specified speed in TMI and check return flow.
c. After the check is complete, stop the test bench and connect the pump return port to pump return port on test bench.
28. Check pump housing pressure.
a. Run the test bench to the specified speed in TMI and check housing pressure.
Setting Timing Advance
29. Run the pump at the specified speed and loosen nut (26) and adjust the trimmer screw with 4C6842 Hex Bit Driver (25) until full advance is achieved.
30. Set cam movement read out device to specified setting in TMI.
31. Run pump at specified speed in TMI and set timing advance to specified setting in TMI.
32. Run the bench at the specified speeds. Make sure flows are correct and the governor is operating properly.
33. If the governor is not operating properly, then stop then bench.
NOTE: The top cover should not need to be remove if the fuel pump was assembled properly. If the top cover does need to be removed, use the following procedures.
Drain Pan Installed
34. Put drain pan (27) under the pump to catch the fuel that will leak from the pump.
Removing Top Cover
35. Loosen bolt (28) to drain fuel from the pump. Remove bolt (28) and remove the three bolts (29) from the top cover (30). Remove top cover (30).
Adjusting Fuel Flow
36. If fuel flow is not correct, remove the front screw and spring. Adjust the internal screws with 4C6842 Hex Bit Driver (31). Both internal screws must be turned equal amounts in the same direction.
NOTE: If the roller-to-roller dimension was set correctly, this step is unnecessary.
37. Install the top cover (30).
38. Recheck for the proper fuel flow and timing.
NOTE: Speed Droop Governors require that high idle speed and final droop adjustments be made on the engine.
39. Turn speed droop adjusting cap in per TMI (Electric Power Generator Engine pumps only).
40. Set high idle per TMI.
41. Set forward shutoff adjusting screw per TMI (aneroid-equipped pumps only).
42. Set low idle per TMI.
Aneroid Adjustments (If Equipped)
Aneroid Adjustments
1. Adjust rear shutoff adjusting screw (2) to get lever travel required from TMI. Lever travel (A) is measured at lever hole (1) as shown.
2. Connect the aneroid rod to pump shutoff lever (3).
Air Pressure Hose Installed
3. Put air pressure hose (5) from 4C8740 Air Supply and Test Group on the aneroid inlet.
Indicator Probe Installed
4. Install indicator probe (6) from 8T1001 Electric Position Indicator on pump shutoff lever (3).
5. Note pressure at which shutoff lever (3) lifts off forward shutoff adjusting screw (4) and the pressure necessary to obtain full travel of shutoff lever (3).
NOTE: Liftoff pressure can be checked by inserting a thin piece of shim stock beneath forward shutoff adjusting screw (4). The shim will slip free as shutoff lever (3) movement begins.
6. If shutoff lever (3) travel requires more pressure than indicated in TMI, lengthen the aneroid rod. If shutoff lever (3) travel requires less pressure than indicated, shorten the aneroid rod
7. After aneroid is set, check response and repeatability.
8. Install the boot to the aneroid body groove.
On Engine Speed Droop Governor Adjustments
1. Start the engine and apply approximately 50% load until the engine reaches normal operating temperature.
NOTE: If the engine surges during the warm-up period, turn the speed droop adjusting cap clockwise until surging stops.
2. When the engine has reached operating temperature, position throttle to get full load speed and apply 100% load. Adjust the throttle if necessary to obtain satisfactory 100% load performance.
3. Remove the load and check for no-load speed per TMI. If incorrect, adjust speed droop adjusting cap in small increments. (Turn clockwise for increased droop or counterclockwise for less droop). If surging exists when load is removed, turn speed droop adjusting cap clockwise to eliminate.
NOTE: When speed droop adjustments are made, throttle position adjustments will also be necessary.
4. Recheck 100% load and no-load performance and readjust as necessary.