The key points for the maintenance and repair of fuel injection pumps are as follows

Fuel cleanliness management
Select light diesel oil that meets the standards. The sedimentation time should exceed 48 hours to remove impurities. Avoid using fuel containing water or mechanical impurities.
Regularly clean or replace the diesel filter element. According to the working environment, promptly remove the sludge and moisture at the bottom of the diesel tank to prevent impurities from corroding the fuel injection pump plunger, fuel outlet valve pair and transmission components.
Engine oil quality and quantity control
Before each start-up, check the oil level and quality in the fuel injection pump (except for forced lubrication models) to ensure that the oil is sufficient and has not deteriorated. Deteriorated engine oil or the mixture of diesel/water can lead to premature wear of the plunger and the oil outlet valve pair, and even corrosion and rusting.
The amount of engine oil must be strictly controlled within the range marked on the dipstick or the oil level screw. Excessive oil can easily cause the diesel engine to "run out of speed", while insufficient oil will lead to poor lubrication.
Regularly change the engine oil and clean the oil pool to thoroughly remove impurities such as sludge at the bottom to prevent secondary pollution.
The fuel supply Angle should be calibrated regularly
Fuel supply advance Angle: Check and adjust when installing the fuel injection pump. Recalibrate after the diesel engine has been running for 500 hours to ensure combustion efficiency.
Fuel supply interval Angle: Regularly check the fuel supply interval Angle of each cylinder to prevent Angle deviation caused by loose coupling bolts or wear of the camshaft/roller body, which may lead to difficult starting, insufficient power or unstable operation.
Adjustment of fuel supply balance
Regularly check and adjust the fuel supply to each cylinder to ensure uniformity. The difference in fuel supply can be judged by observing the color of the exhaust smoke, listening to the engine sound or touching the temperature of the exhaust manifold to prevent power reduction or fuel consumption increase due to uneven fuel supply.
Standardized replacement of high-pressure oil pipes
The length and diameter of the high-pressure oil pipe must comply with the original factory design standards. When damaged, oil pipes of the same specification must be replaced. Non-standard oil pipes can change the fuel supply advance Angle and fuel supply volume, resulting in unstable operation of the entire machine.
Wear monitoring and replacement of key components
Plunger and oil outlet valve pairs: Regular disassembly and inspection are required. When wear exceeds the limit (such as the fit clearance exceeding 0.0005mm), they should be replaced immediately to prevent insufficient oil supply pressure due to internal leakage.
Camshaft clearance: The axial clearance should be controlled within 0.03-0.15mm. If it is too large, gaskets should be added for adjustment or new ones should be replaced. The bearing needs to be replaced if the radial clearance is too large.
Keyways and bolts: Inspect the wear of the keyways on the camshaft, the flange keyways of the coupling, and the semi-circular keys. Repair or replace them in a timely manner to prevent changes in the fuel supply advance Angle.
Maintenance of attachment integrity
Ensure that the side cover of the pump body, the oil dipstick, the oil filling plug (breather), the oil overflow valve and other accessories are intact. The side cover can prevent dust and water. The breather (with a filter screen) can prevent the engine oil from deteriorating. The overflow valve maintains the stability of the fuel system pressure.
Special treatment for long-term disuse
When a diesel engine is idle for a long time, the fuel injection pump passage should be filled with diesel or anti-rust oil should be added, and it should be stored in a dry environment to avoid contact with the battery and acidic or alkaline substances. The anti-rust oil must be thoroughly removed before reuse.
Professional maintenance and debugging
The fuel injection pump should be fully disassembled and inspected every 2,000 hours of operation, with worn parts replaced and re-adjusted. The debugging content includes the fuel supply starting point, fuel supply interval Angle, governor characteristic curve and fuel supply volume at each speed to ensure that the parameters meet the standards.
Operation norms and exception handling
Do not disassemble the fuel injection pump at will, especially the parts with sealing marks. If maintenance is required, it should be carried out in a clean place.
When abnormal operation of the fuel injection pump is detected (such as excessive or insufficient fuel injection volume, unstable operation), promptly check for issues with the fuel system, governor or fuel supply Angle. If necessary, send it to a professional repair institution.