Diagnosis of oil circuit faults by troubleshooting

Use troubleshooting method to diagnose oil circuit fault

1. Troubleshooting method for non fuel injection. First, run out of fuel or. In the oil and natural gas industry, if the fuel tank switch is not opened, there is air in the oil circuit, and the filter or low-pressure oil circuit is blocked, check it. During inspection, just disassemble the low-pressure oil pipe joint close to the high-pressure oil pump. If there is oil overflow in the pipe, it indicates that there is oil in the oil tank, the oil tank switch is unblocked, and the filter and pipeline are not blocked. If there are bubbles in the overflow oil, it indicates that the main reason why the oil cannot be sprayed is that there is air in the oil circuit and gas generation resistance. If there is no bubble in the spilled oil and it is normal oil flow, you can deny the first inspection, and then check the last reason, that is, the spring of the fuel injection pump is broken. During the inspection, for the sake of accuracy, first loosen the adjusting nut of the fuel injection nozzle by half a turn to one turn. If the oil still cannot be sprayed, it is the problem of the oil pump. When checking the oil pump, remove the high-pressure oil pipe, press it firmly on the pipe orifice of the tight seat of the oil return valve with your thumb, and then shake the crankshaft with the oil injection method. If the oil pressure is large, it is difficult to press it with your thumb, indicating that the oil pump is in good condition; If the oil pressure is not large, it indicates that the oil pump coupling is seriously worn; If the oil jacking force is very small or you feel very light when jacking up the pump foot with a screwdriver, you can conclude that the oil pump spring is broken

2. Elimination method of thick oil mist. First try to adjust the adjusting nut of the fuel injection nozzle to see if the oil mist can be improved. If the fuel pump and the fuel injection nozzle are worn, they cannot be improved. For the diagnosis of the wear of the oil pump coupling and the fracture of the working spring, just turn the top foot of the oil pump away from the working position of the camshaft, release the accelerator, and press the oil pump foot with a screwdriver according to the above method. If you feel that the top pressure rebound force of the screwdriver is small and uneven, the spring must be broken; If the rebound force is large, but the oil outlet pressure is small, it indicates that the coupling is seriously worn. If these conditions are good, the problem lies in the fuel injection nozzle. When the adjusting nut of the fuel injection nozzle is screwed out and in, it is very loose and tight for a while. It must be that the fuel injection nozzle should work together in China's aluminum industry and automobile manufacturing industry. There is a problem with the spring. When the oil pump pressure is normal, it is difficult to atomize the oil well after adjusting the injection pressure for many times, which must be the wear of the nozzle coupling. When the oil nozzle works, insert an iron wire of appropriate thickness into the oil nozzle body from the central hole of the adjusting nut, and press the upper end of the iron wire by hand. When there is no jacking force during oil injection, it means that the oil nozzle head is burned

3. Troubleshooting of fuel injection bias. When the fuel injection is biased, the problem can be solved as long as the needle valve coupling of the fuel injection nozzle is intensively checked for wear and carbon deposition

4. Troubleshooting of oil dripping during fuel injection. Remove the tight seat and the oil outlet valve spring, and use your thumb to push forward. First, take the resource-saving development path (i.e. the oil outlet needle valve cannot deflect on the seat), press the oil outlet valve, open the accelerator and rotate the crankshaft. If you feel a great force to push up your thumb during oil supply, it indicates that the oil outlet valve coupling is good. If the jacking force is small and the jacking height is small, it indicates that the coupling parts are worn; if the jacking force is small, it indicates that the diesel oil is sprayed in mist from the sealing cone, and the coupling parts have been seriously worn at this time

5. Exclusion methods for close or remote range. It is mainly to adjust the injection pressure or find out the causes affecting the pressure with the above methods and eliminate them