FUEL INJECTION PUMP

3. Position the spindle, spring, upper spring disc, and spring adjusting nut on the nozzle holder.

Turn the adjusting nut in until pressure can be felt on the spring. 4. Connect the injector to the injector test fixture.

Turn the adjusting nut in or out as required to obtain a nozzle opening pressure of 2750 psi. 5. Position a new copper gasket over the spring adjusting nut and install the injector cap nut.

Repeat the nozzle opening pressure test to make certain it has not changed. 6. Test the injector as previously outlined on page 115. If, after cleaning, the injector fails to pass these tests, the needle and nozzle should be replaced.

F. Installation

1. Drop a new injector seat washer into each injector bore. Make certain that each washer lies flat in the bore. 2. Install each injector by positioning the nozzle end into its bore in the cylinder head and by

guiding the injector rubber seal into its slot in the cylinder head. 3. Work each assembly downward by hand as far as possible.

NOTE: Do not use a hammer to seat the injectors.

4. Align and install the mounting bolts. Torque each bolt to 15 ft. lbs. 5. Install the push rods by lifting the valve rocker arms with a 112" box wrench as previously out· lined for injector removaL 6. Adjust the valve lash 0.014" to 0.016" for both exhaust and intake valves. Connect the injector excess fuel return line to the injectors and at the "tee" connection in the cylinder head. 7. Install the valve rocker cover and gasket, but do not connect the pressure lines to the injector inlets until after the injectors and lines have been flushed as outlined in Paragraph B, page 110. 8. After flushing and bleeding the injection system, reset the valve lash with the engine at normal operating temperature, 180" .

FUEL INJECfION PUMP

The fuel injection pump is mechanically driven by the engine camshaft and is self lubricated. Other than replacing the assembly as a complete unit, the only other servicing requirements are replacement of the pump drive shaft and seals, pump drive gear, pump to engine timing, and throttle speed adjustments.

A. Removal

1. Close the fuel tank shut-<>ff valve and clean all dirt from the pump and injector line connections. 2. Disconnect the four pressure lines from the injector inlet connections and from the pump. 3. Disconnect the fuel line at the pump head and the excess fuel return line at the pump cover connection. 4. Disconnect the throttle linkage at the pump. 5. Remove the two nuts and washers from the pump mounting flange and remove the pump assembly and its drive shaft from the cylinder block as a unit. Use a drain pan to catch any fuel leakage.

NOTE: 1/ the drive shaft does not remain in the pump, fuel may leak into the engine crankcase during pump removal. B.Pump Drive Shaft Inspection

The injection pump drive shaft utilizes "U" cup seals, which may be replaced if defective. In addition, the shaft is serviced as an assembly for replacement purposes. 1. Carefully pull the shaft out of the pump housing with pliers and check the seals for cuts or tears. 2. Lubricate the new seals and "0" ring in diesel fuel to avoid damage and to facilitate ease of installation on the shaft. Carefully install the new seals onto the shaft with the sealing lips toward the ends of the shaft. Install the "0" ring on the shaft. 3. Lubricate the complete shaft assembly with diesel fuel. NOTE: The stepped end 0/ the shaft must be at the lower end 01 the pump a/tel' it is installed.

4. Slide the drive shaft into the shaft bore of the pump as far as the seals. Carefully rotate the shaft and at the same time work the shaft into the pump. 5. Rotate the shaft so that the drive tang is fully seated in the distributor rotor. When the shaft is

Figure 1S-Removing Pump Drive Gear

correctly positioned, the drive tang shoulder at the opposite end of the shaft will be approximately Yt l)" below the top of the shaft bore in the pump.

C. Pump Drive Gear Servicing

The pump gear, shown in Figure 18, is driven by an integral gear on the camshaft and, in turn, drives the injection pump drive shaft and the engine oil pump. NormaHy, this drive gear is removed only if it is to be replaced or when engine overhaul requires its removal.

Pump Drive Gear Removal:

Position a wrench or wide blade screwdriver in the slot of the drive gear and turn it clockwise to remove the drive gear from the engine as shown in Figure 18.

Pump Drive Gear Installation:

The fuel injection pump must be timed with the valves, therefore, it is extremely important that the pump drive be installed correctly to insure proper timing of the pump. 1. With the engine rocker cover removed, crank the engine over until No.1 cylinder is on compression. 2. Check the flywheel timing and adjust for 18" BTDC on 172 cu. in. engines or 20" on 144 cu. in. engines. 3. Initially position the pump drive gear in the bore of the cylinder block so that the slot is approximately vertical and proceed as follows: (a) Rotate the gear counterclockwise about V. turn to instalL

(b) When propedy meshed, the slot in the top of the gear will be approximately horizontal as shown in Figure 19.

IMPORTANT: The slot in the top 0/ the gear is oD center in relation to the counterbore. When the gear is properly installed, lite larger radius 0/ the counterbore will lace toward the tractor as shown in Figure 19. If the gear is installed in the reverse (with the large radius lacing away from the tractor) the injection pump, when installed, will be 180 0 out of phase.

(c) If the pump drive gear shaft does not enter the oil pump shaft, press down on the gear and crank the engine until it drops into place.

10 NOTE, 20 BTDC - ON 144 CU. IN. ENGINE

NO. 1 CYLINDER ON COMPRESSION

LARGE RADIUS _ TOW ARO ENGINE

W

18 BTDC ON 0- FLYWHEEl

CAM

GOVERNOR CAGE

PUMP DRIVE GEAR PROPERl Y INSTALLED

PUMP TIMING MARKS AliGNED All FOUR STEPS MUST BE TAKEN FOR CORRECT PUMP TO ENGINE TIMING T·266 Figllre 19-1n;ection Pump '0 Engine Timing Seqllen(e