Fuel injector stuck because of why

The disassembled diesel engine often suffers from puffing and smoke, which is mostly caused by stuck nozzles. When the injector needle valve is stuck in the closed position, there will be a regular percussion sound near the cylinder head, which is caused by the pressure waves from the injection pump impinging on the injector. If the injector needle valve stuck in the open state, cut off the oil supply of the cylinder, the different sound and white smoke will disappear; if the needle valve is stuck in the closed state, the cylinder will cut off the oil, cut off the cylinder and supply oil, and the engine will not change on fire. . If the multi-cylinder machine looses the high-pressure copper tube of a cylinder, white smoke and chatter will disappear, and a large number of air bubbles will appear at the unscrewing place, which means that the cylinder needle valve and the needle valve body are stuck in the open position; Touching the injector of a cylinder, if the injector of a cylinder is hotter than other cylinders, it proves that the nozzle of the cylinder is stuck. The reasons for stuck nozzle failure are as follows: a. Dust and impurities are attached to the end of the tubing and the connecting bolts. b. When the parts are being serviced or replaced, they are handled improperly and are not correctly installed. c. The added fuel is not clean. Before the start, the oil in the tank and the filter is not released, so that the fuel is not clean to the fuel pump. d. In the fuel injection nozzle, there is a coke at the shoulder of the fixed nut, there is burning loss; the gasket is uneven; when the injector is installed in the hole of the cylinder cover, the tightening torque of the fixing nut of the pressure plate is too large or uneven; the working temperature of the diesel engine Too high, increased fuel injector heat load, etc. e. The fuel injection pressure is not adjusted correctly; the injection pressure adjustment screw is loosened, the pressure regulating spring is broken, and the steel ball in the top dimple pocket is seriously worn or even damaged, which may cause the fuel injector to jam. If the injector is jammed, the stuck injector should be put into diesel or oil to warm up, and then it should be taken out and wrapped in cloth. Then pinch the needle valve with hand pliers and move slowly to take the needle valve from the needle. Remove the valve body. A small amount of clean oil is dripped in the needle valve body, so that the needle valve moves repeatedly in the needle valve body until the needle valve can move freely in the needle valve body. If the sealing surface of the needle valve has burn marks, it should be ground with a grinding paste. Grinding should pay attention to the amount of grinding paste and grinding time. Install the cleaned needle valve coupler on the injector and adjust the injection pressure to reuse it.