Chapter 4 of the text: diagnosis and maintenance of diesel supply systems section i: diagnosis of common failures of diesel supply systems section ii: inspection and adjustment of diesel supply systems section i: diagnosis of common failures of diesel supply systems section i: diagnosis of common malfunctions of diesel supply systems : diesel units work in a similar manner to petrol machines, unlike diesel engines, which use the self-burning capacity of diesel and compress air, which compresses more than gasoline. Diesel is used to spray high-pressure high-speed sprays into high-pressure high-temperature cylinders, which are formed to burn after mixing. The most common failures in the supply of diesel engines are engine start-up difficulties, engine power shortages, accompanied by black smoke, white smoke, blue smoke, engine failure and engine shock. The next page returns the first section of the analysis of common malfunctions in the diesel engine supply system , the difficulty of starting 1 failure the engine curve is driven by the motive to start the rotation, but the engine cannot be activated, usually in the form of: 1 not hearing the sound of an outbreak, no smoke coming out of the exhaust pipe, no activation. 2 discontinuous outbreaks can be heard at start-up, with small or large amounts of smoke discharged from the exhaust pipe but not capable of being activated. The substance of the first phenomenon is that the diesel has not entered the cylinder and the cause of the failure should be found in the transport of fuel; the second phenomenon is that the diesel has entered the cylinder but has not been properly organized to burn, and the cause of the failure should be found in the fuel supply moment, fuel mistification, pressure and temperature of the tank at the end of the compression, which causes the engine to fail: 2 the radio was not returned. 3 diesel filter pelt. 4 oil pump failure: entry filter blocked, piston spring broken, piston badly worn or piston, stick hair card. There is air on the 5-oil road and the pipeline is broken or the pipe is leaked and blocked. Water is available on the six oil routes, which are blocked by winter ice. The 7 diesel plates were wrong, using summer oil in winter, condensed and distilled paraffins, and blocked the roads. 8 oil pump damage: air inside the pump, oil pump for fuel poles that were stuck in unoiled position, oil door-manipulated poles that were removed, oil pump driver coaxies damaged, motors unable to drive oil pump, and stubble damage. The nine jets do not spray oil: the needle valves are stuck in a closed position, the vents are blocked with carbon and the oil pressure is overadjusted. The next page in the previous page returns the first section of the analysis of common malfunctions in the diesel supply system (2) the reason why diesel fuel enters the gas tank and is not properly burning is that 1 is too late for fuel: inappropriate adjustment, adjustment bolts loose on the axis. 2 oil supply is too small: damage to low-pressure oil spill valves results in insufficient pressure for oil supply, resulting in reduced oil supply from jet pumps; poor sealing of oil valves from jet pumps; and severe wear and tear of pyres. Poor spray quality: the adjusted pressure of the jet was too low and the needle valve was badly worn. 4 diesel contains moisture. Five air filters are dirty. Six out of control. 7 gas tank pressure inadequate: inadequate gap between doors, cylinders not sealed. 8 low external temperature and failure of the preheater. The following page returns the first section of the common failure diagnostic analysis of the diesel supply system 3 failure diagnostic failure of the diesel engine cannot be activated and the exhaust pipe is non-smoking, which is mainly due to the fact that the diesel supply system is not working and cannot be sprayed into the combustion room. In diagnosing the failure, it should first be determined whether the failure is a low-pressure or high-pressure road in the diesel supply system. This can be done by first pumping the gas-jet pump with a piping pump. In the case of no-fluorinated or foamed diesel, low-pressure road failure is indicated. If the flow of oil in the vents is normal and no bubbles appear, but no oil is released from the cylinders, this means that the failure occurs on the high pressure road. The following procedures should be followed for diagnosis and exclusion: the following page returns section i. Diagnosis and analysis of common malfunctions in the supply of diesel fuel units (1). 2-tip pine-jet oil pumps with gas-jet bolts and hand-pumps. If a bubble is caught in the fuel flowing from the vent, it is indicated that there is air in the pipeline, and the reasons should be determined whether it was caused by the lack of sufficient oil in the tank, the looseness of the pipeline, the tight sealing of the diesel filter liner or the breakdown of the pipeline. In addition, care should be taken as to whether there are cracks or leaks at the welding point of the upper pipeline inside the tank. Pumping oil through hand-pumps, which, if it is felt to be unoiled, means that there is congestion or damage in low-pressure oil routes, and that diesel filters and pipes should be checked for congestion. The next page of the previous page returns the first section of the common failure diagnosis of diesel fuel supply systems. At the time of the inspection, the pumping of oil from hand-pumps without the normal resistance to pump oil and the repeated failure of pumps to pump oil means that the hand-pump pistons are worn out, that the pump has a sticky or unsealed oil valve, that the spring is broken and should be removed and repaired. 5 pulls out the handle of the hand-pumps, which, if they feel clearly charged, release the handle and automatically return to position, indicates that the pump is blocked in the tank, and that the diesel filter and the pump should be removed and cleaned into the pipeline. If the handle is uninhaled, but there is a high resistance when the handle is pressed, this means that the oil route between the pump and the pump is blocked. Inadequate sealing of the hand pump covers can also cause the pump to pump oil in bad condition. Plugging pipelines, so that diesel is selected with the required number and the necessary seasonal maintenance of the engine. The next page of the previous page returns the first section of the common failure diagnostic analysis of the diesel engine supply system (2) the high-pressure fuel supply section 1 to check that the doorbar has fallen. 2 checks whether the high-pressure pipelines are leaking because of a break or a loose joint. 3 removes the side covers of the pumps and checks whether the oil-regulating poles are moving flexibly and whether the springs of the cavities are broken to hold or the pistons are stuck in the upper position. Whether the fork-for-kilogram regulator for the fork or tooth-barging regulator's fang fixed bolts were loose, and the arm was removed. 4 turns on the engine and touches the tanks with its hands. The pulse of the oil spray indicates that the failure is not in the pump but in the jet. In the absence of an oil spray pulse or a weak pulse, this indicates that the failure occurred in the jet, as shown in figures 4-1. Next page returns charts 4-1 returns section i. Diagnosis of common failures in diesel fuel supply systems 5 if the pump fails, removes the pump's high-pressure pipeline and pumps the oil with hand. When pumping oil, if there is an oil spill at the exit valve, it is shown that the valve is worn out or sealed, that the spring of the exit valve is broken or that the seal surface is contaminated, figure 42. • if no oil spills from the oil valves, check for air in the high pressure roads. The lever can be placed in the position of the maximum supply of oil, with a screwdriver plying the pump plume (chart 42) to pump the oil, so that diesel can be pumped out of the valve until no bubble is caught. Tighten the high-pressure pipeline and pry the pump springs several times, so that the jet can eject diesel, until the sound of a clean pump is heard, the failure can be resolved. In case of a malfunction, the jet can be removed from the roof of the tank, the jet can be brought to the high-pressure pipeline outside the tank, and the oil pump canal plugged into the spring with a screwdriver. If the oil is of poor quality, the oil dispenser should be detached to see if the spring power is normal, if the vent is plugged, if the needle valve is stuck, etc. The diagnostic frameworks for the diesel engine start-up difficulties are shown in figure 43. Next page returns figure 42 returns figure 43 returns section i. Diagnosis of common failure analysis of diesel fuel supply systems diagnosis of low pressure road failure as shown in figure 44. the diagnosis box for high pressure oil road failure is shown in figure 45. ♪ two, slow, slow ♪ it's easy to put out the fire when it's not working。2 reason for failure 1 uneven provision of fuel: oil pump piping plume worn out and valves not sealed; oil pump valves worn out, severe closures, jamming and venting; oil pump work irregular; fuel fuel
