Key points for troubleshooting of injector blockage:

1. No fault code or fault code content has nothing to do with the injector;
2. The rail pressure can reach above 25MPa when starting;
3. There is a pulse voltage signal in the injector circuit.

Key points for troubleshooting of injector jams:

1. No fault code or fault code content has nothing to do with the injector;
2. The rail pressure can be established at startup, but it cannot reach 25MPa (no pulse voltage at the injector);
3. There is no oil return from the injector when the engine cannot be started;
4. Remove the fuel injector after starting, there are signs of fuel injection at the front of the fuel injector

The main points of the investigation of the large amount of oil returned by the fuel injector:

1. No fault code or fault code content has nothing to do with the injector;
2. The low pressure oil circuit is normal;
3. The rail pressure cannot reach 25MPa;
4. Disconnect the oil return pipe of the fuel injector and observe that the oil return is large;
5. If you check which cylinder injector has a large amount of oil return, you can replace the injectors one by one to observe whether the failure phenomenon disappears.

PS: Under normal circumstances, when the injector is not energized, the rail pressure reaches
The fuel injector only starts to return oil when it reaches 60MPa.