- Improper fuel injection timing can cause poor engine performance. The engine timing gears have a reference mark on each gear. Rotating the fuel pump relative to the pump gear changes the fuel injection timing.
Note: The engine is not timed with a pin. The engine has an idler gear with an odd number of teeth. Do not rotate the engine if the fuel injection pump is removed. The engine must be timed again if the engine is rotated after removal of the fuel injection pump. The gears must be aligned by using the timing marks once the front housing is removed. Mark the teeth with a paint stick. Reinstall the fuel injection pump by meshing the marked teeth.
- Timing marks (1) and (2) on the fuel injection pump indicate the pump position relative to the timing gear. Each mark on the scale represents a change in timing of six degrees.
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Illustration 1 | g01227078 |
Fuel injection pump timing mark (1) Timing mark on the fuel injection pump (2) Timing mark on the engine block |
- Loosen the retaining bolts. Rotating the fuel pump toward the engine advances injection timing while rotating the fuel pump away from the engine retards injection timing.
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Illustration 2 | g01227082 |
Adjusting fuel injection pump timing For 3046 Engines Only (X) Direction of retarding timing (Y) Direction of advancing timing |
- To check the fuel injection timing, disconnect the fuel injection line from the fuel injection pump. Loosen the clamp and remove the delivery valve holder. Remove the valve spring and the stopper from the delivery valve holder. Replace only the delivery valve holder. Install a new fuel line to the delivery valve holder.
- Turn the crankshaft until the No. 1 piston is approximately 60 degrees BTC on the compression stroke.
Note: Check the valve lash with the No. 1 cylinder at the top center position. This ensures that the cylinder is on the compression stroke and that the cylinder is not on the exhaust stroke.
- The crankshaft pulley contains a scale that has a range of 0 degrees to 40 degrees. The first mark on the scale represents 0 degrees. Each mark on the scale after the first mark represents a 5 degree crankshaft rotation.
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Illustration 3 | g01227084 |
Crankshaft pulley timing marks |
- Operate the fuel priming pump. Rotate the engine crankshaft until the fuel stops flowing. Read the number of the timing mark on the crankshaft pulley that is indicated. The number of the timing mark should be within ± 1.5 degrees of the number on the emission sticker. The emission sticker is located on the top of the valve cover. Refer to the Technical Marketing Information (TMI) for other technical data. To correct the fuel injection timing, rotate the fuel pump. Refer to Step 3.
NOTICE |
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Use a suitable container to catch any fuel that might spill. Clean up any spilled fuel immediately. |
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Illustration 4 | g01227085 |
Checking for fuel flow (3) Fuel priming pump |