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Fault Causes Of Diesel Generator Fuel Injection Pump Failure To Supply Fuel

Jan. 04, 2023

The wear of the sealing cone of the outlet valve of the diesel generator is caused by the residual pressure of the outlet valve spring and the high-pressure oil in the high-pressure oil pipe when the outlet valve is playing the role of reducing pressure, which causes the valve core to hit the sealing cone of the valve seat, and at the same time, the effect of the impurities (abrasives) in the diesel. The wear of the pressure relief ring and the seat hole is mainly caused by the impurities in the diesel oil.


If the outlet valve is poorly sealed due to dirt, it can be installed and reused after being cleaned with gasoline. If the conical surface of the oil outlet valve is worn and not tightly sealed, the conical surface can be slightly coated with chromium oxide and ground with engine oil. After grinding, it shall be cleaned with gasoline. The ground surface shall be free of grooves and arcs, and the sealing shall be tight. If the wear is serious, replace it. If the pressure relief ring belt is excessively worn, the surface is dark. If there is a groove after careful observation (or magnification), it should be replaced.


Fuel injection pump does not supply fuel cause:

① There is no oil in the oil tank or the oil switch is not opened.

② Diesel filter plug.

③ There is a lot of air in the oil circuit.

④ The plunger spring of the injector is broken.

⑤ The column coupling (column coupling and plunger sleeve) is excessively worn.

⑥ The column is stuck.

⑦ The screw groove of the plunger is installed incorrectly.

⑧ The outlet valve is excessively worn or the outlet valve is padded with dirt.

⑨ The outlet valve spring is broken or the elasticity is weakened.

⑩ The plane contact between the outlet valve and the plunger sleeve is not tight (if there are impurities), which causes the diesel oil to fall out of the gap of the contact surface, and the fuel injection pump does not supply fuel because the valve does not open.

⑪ The outlet valve gasket is broken. If no fuel is supplied to all cylinders, the diesel engine will not work at all. If individual cylinders do not supply oil, it is difficult for the diesel engine to start. Even if it starts, it will not work smoothly.


diesel generator


① Check whether there is diesel in the diesel tank, whether the fuel tank switch is open, and whether the air vent of the fuel tank is blocked.


② Unscrew the air release screw of the diesel filter and the fuel injection pump, pump the oil with the hand pump or rely on the gravity of the diesel (depending on different models). If there are bubbles in the diesel oil flowing out of the vent screw, it indicates that there is air leakage in the oil circuit. The cause should be found out: insufficient diesel oil in the oil tank, loose oil pipe joints, cracked oil pipes and untight sealing gaskets. After troubleshooting, continue to pump oil with the hand pump or flow by the gravity of diesel until there are no bubbles in the diesel. Then tighten the bleed screw and the hand pump. If you feel that the oil is not smooth when pumping oil with the hand pump or flowing by the gravity of diesel oil, it indicates that the low-pressure oil circuit is blocked. Check whether the diesel filter and low-pressure oil circuit are blocked. If there is oil leakage in the low-pressure oil circuit, it will also cause the oil to be blocked. If it is good after inspection, the fault is inside the oil transfer pump, which should be disassembled for inspection.


If you still have questions, please contact Jiangsu Starlight Electricity Equipments Co.,Ltd. We will provide you with a professional diesel generator purchase guide and configure a suitable diesel generator set for you. Looking forward to your inquiry, please send email to us for details sales@dieselgeneratortech.com.

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