How should the fuel injection pump be maintained?

The fuel injection pump is an important part of the diesel fuel supply system, and its working condition directly affects the power, economy, and reliability of the diesel engine. Proper maintenance is an important prerequisite to ensure the normal operation of the fuel injection pump and extend its service life. Proper maintenance should do the following.

(1) Use good diesel and filter to ensure that the diesel entering the fuel injection pump is highly clean. In general, diesel engines have much higher requirements for filtered diesel than gasoline engines. When used, you must choose the required brand of diesel, at least 48h will precipitate. Strengthen the cleaning and maintenance of the diesel filter, clean or replace the filter element in time; Clean the diesel tank in time according to the operating environmental conditions, and thoroughly remove the sludge and water at the bottom of the tank. Any impurities in diesel fuel can cause serious corrosion or wear to the plunger of the fuel injection pump, the coupling of the oil outlet valve, and the transmission components.


(2) Regularly check and adjust the fuel injection pump oil supply advance Angle and the cylinder oil supply interval Angle. When in use, due to the loosening of the coupling bolt and the wear of the camshaft and roll parts, the oil supply advance Angle and the oil supply interval Angle of each cylinder often change, leading to the deterioration of diesel engine combustion, poor power and economy, and the phenomenon of starting difficulty, unstable operation, abnormal sound, and overheating. In actual use, most drivers pay attention to the inspection and adjustment of the overall oil supply advance Angle but ignore the inspection and adjustment of the oil supply interval Angle (involving the adjustment of the oil supply advance Angle of a single pump). In this way, although the first cylinder has the oil supply timing after the overall adjustment, the other cylinders do not have the oil supply timing due to the wear of the camshaft and roller transmission parts, which will also lead to the difficult start of the diesel engine, insufficient power, and unstable operation. Therefore, for the injection pump with a longer use time, more attention should be paid to the inspection and adjustment of the oil supply interval Angle.

(3) Regularly check and adjust the oil supply of each cylinder of the injection pump. Due to the wear of the plunger coupling and the oil outlet valve coupling, diesel internal leakage will reduce or uneven the oil supply to each cylinder, resulting in difficulties in starting the diesel engine, insufficient power, increased fuel consumption, and unstable operation. Therefore, it is necessary to regularly check and adjust the oil supply of each cylinder of the injection pumpto ensure the power of the diesel engine. In actual use, the fuel supply of each cylinder can be determined by observing the exhaust smoke of the diesel engine, listening to the engine sound, and feeling the temperature of the exhaust manifold.

(4) Regularly check the camshaft clearance. When the injection pump works for some time, we can roughly judge the wear of the plunger and the working condition of the oil pump by checking the seal of the oil valve, which is conducive to determining the repair and maintenance method. During the inspection, unscrew the high-pressure tubing joints of each cylinder and pump oil with the hand pump of the oil delivery pump. If the oil flows out of the tubing joint at the top of the injection pump, the oil valve is poorly sealed (of course, this will also occur if the oil valve spring is broken). If the multi-cylinder seal is poor, the injection pump should be thoroughly debuted and maintained, and the spare parts should be replaced.


(5) Use standard high-pressure tubing. Due to the compressibility of diesel oil, high-pressure diesel oil will form pressure fluctuations in the pipeline during the injection pump. It takes time for the pressure wave to travel through the pipe. To ensure that the oil supply interval Angle of each cylinder is consistent, the oil supply is uniform, and the diesel engine works smoothly, the length and diameter of the high-pressure oil pipe are selected by calculation. Therefore, when the high-pressure tubing of the cylinder is damaged, the tubing of the standard length and diameter should be replaced. In actual use, due to the lack of standard pipes, other pipes are used instead. If the length and diameter of the tubing are the same or different, the length and diameter of the tubing will be very different. Although it can be used in emergencies, the oil supply advance Angle and oil supply amount of the cylinder will change, resulting in unstable operation of the whole machine. Therefore, standard high-pressure tubing must be used in use.

(6) Regularly check the wear of the keyway and fix bolts. Keyways and bolts mainly refer to camshaft keyways, coupling flange keyways (oil pumps that use couplings to transfer power), semi-circular keys, and coupling fixing bolts. Due to long-term use, the keyway, flange keyway, and semi-circular key of the injection camshaft of the pump wear less, making the keyway wider, the semi-circular key installation is not fast, and the oil supply advance Angle changes; Heavy key roll, resulting in power transmission failure, regular inspection, timely repair or replacement of worn parts.


(7) Timely replacement of worn plunger and oil outlet valve accessories. When it is found that the diesel engine is difficult to start, the power is reduced, and the fuel consumption is increased, but the injection pump and the injector are still not improved by adjusting them, the injection pump plunger and the oil outlet valve should be opened for inspection. If the plunger and oil outlet valve wear to a certain extent, it should be replaced in time, and do not insist on repeated use. The loss of diesel engine starting difficulty, fuel consumption increase, and power shortage caused by parts wear far exceeds the cost of replacing parts. After replacement, the power and economy of the diesel engine will be significantly improved, so the worn parts should be replaced in time.


If you have doubts about the maintenance of the fuel injection pump, you can contact us, we can provide you with professional answers and products. 

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