1 Difficulty in starting
1.1 Failure phenomenon
Driven by the starter, the speed of the diesel generator reaches the starting speed, but it cannot start, usually as follows:
(1) There is no explosion sound when starting, no smoke is discharged from the exhaust port, and it cannot be started.
(2) A continuous explosion sound can be heard when starting, there is white smoke or a small amount of black smoke, but it cannot be started.
1.2 Causes of failure
(1) Failure of low pressure oil circuit
1) There is no oil in the oil tank or the oil level is too low, and the suction pipe cannot suck oil.
2) The tubing is broken and the tubing joint is loose and leaking oil.
3) There is air in the oil supply system or the pipeline is blocked, causing the engine to not catch fire.
4) There is water in the diesel, and it freezes in winter, which causes the pipeline to be blocked; the diesel used in winter does not match the label, which causes the diesel to wax and block the filter and oil pipe.
5) If it is not cleaned for a long time, and the filter element of the diesel filter is not replaced, it will cause blockage.
6) The relief valve spring of the fuel injection pump is broken or cushioned by foreign objects, so that the diesel will flow from the low-pressure oil circuit back to the diesel tank, so that the low-pressure oil circuit cannot maintain a certain oil pressure and the engine does not catch fire.
(2) Failure of oil transfer pump
1) The check valve is improperly assembled or used for too long, causing excessive wear on the valve seat surface.
2) The filter is clogged.
3) The plunger of the oil transfer pump is bitten, or the spring is broken, or is severely worn, and the oil transfer pump cannot supply oil normally.
4) The push rod of the oil transfer pump is bitten.
5) The piston of the hand oil pump is not tightly sealed.
(3) Failure of the oil supply drive train
1) The transmission rod of the governor is too worn, so that the oil supply rack rod cannot reach the position of the starting oil volume and the rated oil supply volume.
2) The oil stop cylinder is stuck at the lowest oil level, and the engine cannot be ignited, or the connection part of the oil stop cylinder can fall off.
3) The connecting pin shaft of the joystick is severely worn and can not be used for control.
(4) Failure of fuel injection pump
1) The straightening gear rod is seized, or the plunger is stuck due to the broken spring, so that the oil supply gear rod always stays in the parking position.
2) The plunger is worn too much, or the plunger is stuck in the sleeve.
3) The gears are severely worn, causing the gap between the plunger and the tappet to be too large, causing the pump oil to drop and causing the engine to fail to catch fire.
4) The locking bolts of the oil supply adjustment ring gear are loose or fall off, which changes the oil supply of the pump.
5) There is dirt on the oil outlet valve, or the oil outlet valve spring is broken and oil leaks or a valve is issued.
6) The coupling plate of the fuel injection pump coupling is damaged, or the coupling bolt is loose, which changes the fuel supply time and causes the engine to not catch fire.
7) The connection between the drive shaft of the fuel injection pump and the transmission gear is loose, causing the fuel injection pump to not work.
8) The intermediate timing gear or the fuel injection pump transmission gear is broken.
(5) Malfunction of the injector
1) The high-pressure oil pump joint is loose or the high-pressure oil pipe is broken.
2) The injector is blocked or the injector needle valve is stuck due to overheating.
3) The fuel injection nozzle and its parts are severely worn, oil leaking, and poor atomization.
4) The spray pressure of the fuel injection nozzle changes, and the pressure is too low to burn.
5) The fuel injector is damaged.
6) The gasket is not sealed and leaks air.
1.3 Judgment and elimination of faults
(1) First check the oil level of the fuel tank. If there is no oil or the oil level is too low, it should be filled. After the oil level is full, supply oil with a hand oil pump, and open the bleed plug on the diesel filter to check the oil. Whether there is air in the road, if there is, it should be drained. If the air is not exhausted, check whether the tubing joints are loose and whether the tubing is broken. During the inspection, use a clean towel to wipe the joints and the suspected pipeline ruptures, and then use your hands Observe the oil pump. If diesel oil appears again, it means that the place is loose or broken.
(2) Pump oil with a hand oil pump. If the oil is not smooth, it means that there is a blockage in the low-pressure oil circuit. The oil-water separator (coarse filter), diesel filter and pipeline should be checked. It is especially emphasized that the oil-water separation should be checked Whether the metal filter element in the filter is blocked.
(3) Pump oil with a hand oil pump, and open the screw plug on the diesel filter to check whether there are water droplets in the diesel oil.
(4) When pumping oil with a hand oil pump, I feel that there is no pumping force, and the pump oil does not deliver oil many times, that is, the piston of the hand oil pump is too worn, or the valve is contaminated, or the wear is serious and the seal is not tight. It should be overhauled or replaced. Hand oil pump, if you feel elasticity and resistance when pumping oil, it is very happy when the handle is pressed down, and the handle can be automatically returned to position when the handle is released, indicating that the oil pump’s oil inlet pipe to the oil tank is blocked. At this point, the oil tank is The oil-water separator and the pipeline to the oil transfer pump are all replaced with transparent pressure-resistant plastic pipes, so that the oil flow and blockage can be seen very clearly. In addition, the poor sealing of the hand oil pump cover will also cause the oil transfer pump to fail.
(5) Through the above inspection, if everything is normal, check the working condition of the fuel injection pump, check whether the transmission gear is loose and broken, whether the fuel injection advance angle has changed, and whether the coupling fixing bolt is loose. If the engine fuel injection pump shaft rotates, The high-pressure fuel pipe joint of the fuel pump should be disassembled, the engine should be driven by the starter, and the throttle should be increased. If there is no oil flowing out of the loosened fuel pipe joint of the fuel injection pump, the fuel injection pump should be inspected and verified. The fuel injection pump should be inspected on the fuel pump test bench. Adjust according to the standard.
If after the fuel injection pump is checked, the fuel injection advance angle is normal and still cannot be started, the fuel injector should be disassembled to check the fuel injection pressure and nozzle atomization. If the atomization is not good, it will also cause difficulty in starting the engine.
Be sure to replace the diesel that meets the standard according to the season to prevent the diesel from waxing.
2 Rough work
2.1 Symptoms
The engine is unstable, and the black smoke from the exhaust pipe produces a metal-like knocking sound. The knocking sound is intensified when accelerating, and the knocking sound is weakened or disappeared at high speed, and the knocking sound reappears at idle speed.
2.2 Causes of failure
(1) Due to the loosening of the fixing bolts of the fuel injection pump coupling, the advance angle is too large.
(2) The fuel quality is poor or the fuel supply of each cylinder is uneven, and the fuel supply of individual cylinders is too large.
(3) Long-term high-speed operation, the engine temperature is too high or deflagration occurs.
(4) Severe carbon deposits in the combustion chamber will also produce deflagration.
2.3 Troubleshooting
Adjust the fuel supply advance angle in time and use the correct fuel.
Post time: Oct-14-2021