1.Check the low-pressure oil circuit
(1) First check whether the diesel switch in the lower part of the diesel tank is open. Drain the water and dirty oil in the fuel tank through the drain valve. .
(2) Secondly, loosen the bleed screw located on the pump body of the high pressure pump, pump the oil through the hand oil pump, and observe the oil supply of the low pressure oil to see if it is smooth and sufficient.
(3) If it is not smooth and sufficient, and there is air that is not cleaned, then every link of the pipeline before the hand pump needs to be checked to see if there is any air leakage.
(4) When pumping oil with a hand oil pump, if you feel that it is difficult to get oil and the oil is not sucked, it means that there is a block in the low-pressure oil circuit. At this time, you need to check the diesel filter, filter element or pipeline. There are cases of clogging.
(5) If the temperature is relatively low, you need to check the brand of diesel oil to see if the oil circuit is blocked because of wax precipitation or water freezing. If it is a blockage, it must be eliminated until the oil is sucked smoothly and there is no air bubbles.
(6) Finally, if it is not the failure caused by the reasons mentioned above, then it means that the piston of the hand oil pump is too worn, or the valve is damaged, and the dirt is cushioned, or the hand oil pump seal cannot meet the requirements . At this time, you need to replace the hand pump.
2.Check the high pressure oil circuit
(1) When there is no fault in the low-pressure oil circuit, the diesel engine still cannot start, then the high-pressure oil circuit needs to be checked next.
(2) First, check whether the high-pressure pump oil amount adjustment rack is flexible, whether it is stuck in the oil stop position, or other reasons make the oil supply abnormal.
(3) Secondly, check whether the fuel supply time of the high-pressure oil pump is correct. If the fuel supply time is incorrect, it should be adjusted to the standard timing.
(4) Again, remove the air from the high-pressure oil pipe. If there is air in the diesel high-pressure fuel pipe, it will be difficult to drive the diesel engine by the starter, and the diesel engine will be difficult to start at this time. At this time, you need to loosen the nut of each injector’s high-pressure oil pipe, and then start the starter to drive the diesel engine to start rotating. When each high-pressure oil pipe can spray fuel, you can tighten the high-pressure oil pipe’s connection nut Already.
(5) If the above measures still fail to start, you need to check whether the injector and high-pressure fuel pump are malfunctioning. No matter if the high-pressure oil pump or the fuel injector fails, experiments need to be performed on the test bench, and a special pressure tester must be provided to prevent accidents.
Post time: Apr-20-2020