What are the causes of poor atomization and stuck needle valve in diesel engine injectors? How to judge and eliminate them? How to eliminate stuck needle valve?

The reasons for poor atomization of the fuel injector are:

1) Diesel is too dirty;

2) There is too much carbon deposit between the needle valve and the valve seat;

3) The needle valve is not closed tightly and causes oil leakage;

4) The injection pressure is improperly adjusted, too low or too high;

5) The fuel injector pressure spring is broken or stuck.

The reasons why the needle valve is stuck are:

1) Diesel is too dirty;

2) The injector has poor atomization and oil dripping;

3) The fuel injection time is wrong and the engine overheats;

4) Improper installation of the fuel injector causes local overheating of the fuel injector.

Methods to determine whether the injector needle valve is stuck;

Remove the fuel return pipe of the fuel injector, insert a thin wire into the center hole of the fuel injection pressure adjustment nut, and start the engine. If you feel the wire moving up and down quickly and forcefully, it means the needle valve is working normally. If the wire does not move, it means the needle valve is stuck.

The method to troubleshoot a stuck needle valve is:

1) Remove the fuel injector, remove the needle valve assembly, and replace it with a new needle valve assembly;

2) If the needle valve is stuck in the closed position, it can also be cleaned with diesel and then ground with clean engine oil before use.