Difficulty starting the diesel engine
(1) Check the low-pressure oil line
① Check whether the diesel switch at the bottom of the diesel tank is open, and use the drain valve to drain the water and dirty oil in the diesel tank; check and remove the water and dirty oil in the diesel filter and filter collection.
② Loosen the bleed screw on the high-pressure oil pump body, pump oil with a manual pump, and observe whether the low-pressure oil supply is smooth and sufficient. If there is unclean air in the diesel fuel that needs to be removed, check all links in the pipeline in front of the manual pump for air leaks, such as whether the pipe joint gasket is damaged, whether the pipe joint is tightened, and whether the pipeline is damaged or cracked, etc. When pumping oil with a hand oil pump, if you feel difficulty in oil supply and poor oil suction, it means there is a blockage in the low-pressure oil circuit. You should check whether the diesel filter screen, diesel filter element or pipeline is blocked. When the temperature is low, you should check whether the diesel grade is correct and whether the oil line is blocked due to diesel wax precipitation or water freezing. Eliminate the blockage until the oil suction is smooth and the oil is discharged without bubbles.
③When using a manual pump to pump oil, if diesel cannot be pumped out due to reasons other than those mentioned above, it means that the piston of the manual pump is excessively worn, or the valve is padded and damaged by dirt, or the seal of the manual pump is damaged, and the manual pump should be replaced.
(2) Check the high-pressure oil line
If there is no fault in the low-pressure oil circuit and it still cannot be started, the working condition of the high-pressure oil circuit should be checked.
① Check whether the oil volume adjustment gear rod of the high-pressure oil pump moves flexibly, is stuck in the oil stop position, or is unable to supply oil due to other forms of damage.
② Check whether the high-pressure oil pump oil supply time is correct. If the fuel supply time is incorrect, it should be adjusted to the standard timing.
③ Remove the air in the high-pressure oil pipe. If there is air in the diesel high-pressure oil pipe, it is sometimes difficult to remove it by using the starter to drive the diesel engine, and the diesel engine will also be difficult to start. To do this, loosen the bolts connecting each injector to the high-pressure oil pipes, press the start button (or turn the start key to "Start") and use the starter to drive the diesel engine to rotate until each high-pressure oil pipe sprays fuel, and then tighten the high-pressure oil pipes. Connecting bolts.
④ If the diesel engine still cannot start at this point, check whether the injector and high-pressure oil pump themselves are faulty. The main faults of the fuel injector include burnout, poor atomization, and incorrect injection pressure adjustment. The main problems of high-pressure oil pumps include excessive wear of the plunger pair, resulting in insufficient oil supply pressure and broken speed-regulating springs. It should be noted that the adjustment of the high-pressure oil pump must be carried out on the high-pressure oil pump test bench; the same is true for the fuel injector, which must have a pressure tester.
