If the fuel injector failure is caused by the needle valve being blocked by dirt, the fuel injector should be disassembled for cleaning, repaired and re-adjusted. Due to the continuous spraying and washing of high-pressure oil flow, the nozzle hole of the needle valve will gradually wear out, resulting in a drop in fuel injection pressure. A steel ball with a diameter of 4mm to 5mm can be placed at the end of the hole and gently tapped with a hammer to make the nozzle hole Local plastic deformation occurs to reduce the pore size. Due to the large number of holes and small hole diameter of the multi-hole direct injection injector, the punching sample made of high-speed steel can only be used to lightly tap the hole end. If it is still unqualified after debugging, the needle valve assembly should be replaced. The end surface of the needle valve body is impacted by the frequent reciprocating motion of the needle valve, and pits will gradually form over time, thereby increasing the lift of the needle valve and affecting the normal operation of the injector. The needle valve body can be clamped on the grinding machine This end face is ground and then lapped with a fine lapping paste on the glass plate.
