If the failure of the injector is caused by the needle valve being blocked by dirt, the injector should be disassembled for cleaning, maintenance and re-commissioning. Due to the continuous spraying and scouring of the high-pressure oil flow, the nozzle hole of the needle valve will gradually become larger, resulting in a drop in the injection pressure. You can put a steel ball with a diameter of 4mm to 5mm at the end of the hole, and tap it lightly with a hammer to make the nozzle hole. Plastic deformation occurs locally to reduce the pore size.
Due to the large number of holes and small diameter of the multi-hole direct injection injector, the punching sample made of high-speed steel can only be tapped lightly at the end of the hole. If it is still unqualified after debugging, the needle valve coupler should be replaced. The end face of the needle valve body is impacted by the frequent reciprocating motion of the needle valve, and a pit will gradually form over time, thereby increasing the needle valve lift and affecting the normal operation of the injector. The needle valve body can be clamped to the grinding machine. This end face is ground and then ground on a glass plate with a fine grinding paste.
