1. The diesel oil is not clean, and there are impurities in the high-pressure oil pipe, which makes the needle valve coupler not close tightly, and the high-pressure gas in the combustion chamber reverses and burns out the needle valve coupler. In addition, the dirt on the injector pressure regulating spring, tappet and other parts is moved to the upper part of the injector needle valve through the injector tappet, or the cotton rope and lead wire used to prevent oil leakage on the oil road enter the injector through the high pressure oil pipe The oiler will cause the needle valve coupler to be stuck.
2. The machine temperature is too high and the fuel injector is not well cooled, causing the needle valve coupler to be stuck. The oil supply time is too late, the cooling water channel is too much scale or blocked, the end face of the water pump impeller is worn, and the engine is overloaded for a long time, which will cause the engine to overheat.
3. The oil outlet valve is worn, so that the oil dripping phenomenon occurs when the injector stops injecting fuel, so that the nozzle is burned with coke and coke, and the failure of jamming occurs.
4. When the injector is installed, the gasket is missing or damaged, causing air leakage and causing the local temperature of the injector to be too high and stuck.
5. The fuel injection pressure is too low, causing the high-pressure gas in the combustion chamber to reverse;
6. Reasons for parts manufacturing, such as the installation hole of the injector on the cylinder head is too tight with the injector, the gap between the needle valve body and the installation hole on the cylinder head is too small, the installation hole of the cylinder head injector is too deep, etc. .
