(1) Wear of the fuel injection pump causes diesel to enter the engine oil: the engine oil level increases significantly and is accompanied by a diesel smell. In severe cases, oil leaks out from the oil filling port or vent. For piston-type fuel pumps, there are only two ways for diesel to enter the engine oil: diesel can directly enter the lubricating oil in the lower chamber of the fuel injection pump from the side gap of the fuel pump roller body; the fuel injection pump slave pump plunger pair is worn beyond the limit, causing internal leakage of the slave pump, and the leaked diesel will flow into the lubricating oil.
Handling measures: Open the side cover of the fuel injection pump and start the engine. If diesel splashes out of the slave pump plunger, it means that the slave pump plunger pair is worn beyond the limit and needs to be replaced. The plunger pair should be calibrated on the test bench. Remove the fuel pump and use a hand oil pump to pump oil. If diesel leaks out of the side gap of the fuel pump roller, it proves that the fuel pump is faulty. You can also remove the oil pump and the connecting oil pipes, tighten the hand oil pump, block the oil outlet of the oil pump, and introduce gas with a pressure of 0.4MPa from its oil inlet. If gas comes out of the roller side gap, it proves that the oil pump is faulty and should be replaced.
(2) Oil leakage at the joint between the fuel pump outlet and the high-pressure connection: The concave fuel pump outlet and the convex high-pressure connection are worn, resulting in poor sealing and oil leakage.
Treatment measures: Add a concave round copper pad to the concave joint of the fuel pump outlet. This pad is available in all school pump factories and can be given away free of charge with the school pump. This method can also be used to treat oil leakage at the connection between the fuel injector and the high-pressure oil pipe. Practice has proved that the effect is very good.
(3) Fuel injection pump shaft broken: If the four fine-thread bolts of the fuel injection pump are not tightened, the loose pump and the pump seat will rub dry when the engine is running, and the gap will become larger. Finally, the installation position of the fuel injection pump will be displaced, and the fuel injection pump and the drive shaft will be out of center, causing the shaft to break.
Treatment measures: Use copper sheet of appropriate thickness as a pad between the pump and the pump seat. Eliminate the gap. When reinstalling the fuel injection pump, clean the threaded hole first, then tighten the four fixing bolts to the specified torque, and check the coaxiality of the fuel injection pump shaft and the drive shaft. If it does not meet the standard, readjust it. It is recommended to remove the fuel injection pump together with the pump seat.
