See Figure 1
This procedure is performed with the injection pump installed.
- With the engine running, loosen the cap on the fuel injection line at the injection pump outlet. This will relieve pressure and prevent fuel injection into the cylinder.
- If a cylinder is misfiring, uneven combustion will stop when the fuel is cut off.
- Proceed from cylinder to cylinder until the faulty cylinder is located.
- Perform a compression test on the cylinder in question. If the cylinder in question meets the compression specifications, replace the injection pump.
REMOVAL & INSTALLATION
See Figures 2 and 3
- Disconnect the batteries.
- Disconnect the fuel shutoff rod at the stop lever.
- Remove the power steering pump and the mounting bracket from the engine and set it aside.
- Thoroughly clean the area around the hose fittings and the injection pipes.
- Drain the engine oil and remove the dipstick and the dipstick tube.
- Disconnect the throttle cable and the linkage from the injection pump control lever.
- Remove the throttle control bracket assembly from the crankcase, injection pump and the control bracket and set it aside.
- Disconnect the fuel supply line to the fuel feed pump and set it aside, loosening the anchoring clamps as necessary.
- Disconnect the fuel hoses leading to the filter from the feed pump and the injection pump. Replace the screws and seals to prevent dirt from getting into the pump.
- Rotate the engine so piston no. 1 is approximately 7° before top dead center on the compression stroke.
- Disconnect the injection pipes from the delivery valves and set them aside. Cap the ends of the valves to prevent the entry of dirt.
- Disconnect the injection pump lube lines.
- Remove the five screws and one bolt attaching the pump.
- Pull the pump to the rear and disengage it from the front plate and timing gear case. Rotate the pump toward the crankcase and continue pulling it to the rear until the automatic timer is freed.
- Loosen the four nuts attaching the pump to the mounting flange plate and align the center timing mark on the pump flange with the pointer on the plate. Tighten the four nuts.
- Be sure that the O-ring is in place on the forward face of the pump mounting flange.
- Remove the threaded timing port plug on the governor housing behind the control lever to expose the camshaft bushing timing mark. Rotate the pump drive gear to align the timing mark on the camshaft bushing with the pointer on the governor. The guide plate notch will be approximately the 8 o'clock position as viewed from the front. Be sure the engine is positioned as described in step 10 of the removal procedure.
- Insert the automatic timer into the timing gear case and with the injection pump rotated against the crankshaft, rotate the pump driver gear to mesh the drive and idler gears. Do not force the pump into position.
- Push the pump forward into the case. Rotate it away from the crankcase to align the attachment holes.
- Attach the pump to the timing gear case.
- Rotate the engine crankshaft in the opposite direction of normal operation until the crankshaft reaches the 18° before TDC mark on the crankshaft pulley. The governor pointer and the injection pump camshaft bushing timing marks should now be aligned. If they are not aligned, the pump has been installed incorrectly and must be removed and reinstalled.
- Install the governor housing timing port plug and proceed with the pump installation by reversing the remainder of the removal procedure. Do not connect the no. 1 injecting pipe, fuel control rod or the batteries.
- Bleed the air from the fuel filter and the injection pump by removing the air bleeder screws.
- Time the injection pump.
INJECTION PUMP TIMING
See Figure 4
- Disconnect the batteries and the fuel shut off rod at the stop lever.
- Rotate the crankshaft in the direction of normal operation until no. 1 cylinder reaches top dead center of the compression stroke. This is done by aligning the lines on the crankshaft pulley rear face with the pointer on the bottom of the case.
- Remove the forward oil filler cap on the rocker cover and check the no. 1 cylinder valves for looseness. If they are loose, you are at TDC.
- Rotate the crankshaft in the normal direction of engine operation 1 3 / 4 turns.
- Disconnect no. 1 injection pipe from the delivery valve holder.
- Turn the crankshaft in the normal direction of engine operation in small steps. Stop when fuel begins to flow from the delivery valve holder. Injection begins at this point. The control lever must be in the idle position.
- Read the injection timing point from the scale on the back of the crankshaft damper. If the timing is correct, the timing mark should be at the value shown on the Vehicle Emission Control Information label on the rocker cover +- 2 degrees.
- If the timing point determined differs from the standard value, minus 2 degrees, loosen the four pump-to-flange plate nuts and rotate the pump (toward the crankcase to advance the timing, away from the crankcase to retard it) to correct the difference. Each mark on the injection pump timing scale represents 6 degrees. Tighten the flange plate nuts and repeat the timing procedure to be sure the timing is correct.