Some maintenance points check and adjust the fuel injector assembly too extensively. Some only check and adjust the fuel injection pressure at the beginning, and some items that should not be simplified have been reduced. This is wrong. We believe that the adjustment should be carried out according to the process specifications. Not only should the standard fuel injection pressure be checked and adjusted, but also the spray cone angle, fuel injection quality, etc. should be further checked according to the specific situation, especially for the tightness of the fuel injector. arouse full attention.
Check the tightness of the fuel injector: Carry out on the fuel injector tester, take the multi-hole long fuel injector as an example, raise the predetermined pressure of the fuel injector tester to 2324 MPa, and increase the fuel injection pressure of the fuel injector to 24 ~ 25 MPa, when the pressure of the injector tester drops from 20 MPa to 18 MPa, the standard injector duration should be 9 ~ 20 s, and the allowable use should not be less than 9 s.
It is worth noting that: first of all, the injector tester must meet the technical requirements, the high-pressure oil circuit should be tight, and the sealing performance of the oil outlet valve assembly itself on the tester should be good. Exclude the air in the oil circuit, block the high-pressure oil outlet connector, continue to supply oil and increase the pressure, so that the predetermined pressure rises to 23~24 MPa. When the pressure of the tester drops from 20 MPa to 18 MPa, the duration should not be less than 3 minutes. Secondly, the fuel injector should be inspected no less than twice, and the average value should be taken. And the time difference between two adjacent times shall not be greater than 2 s for pintle and plate type, and shall not be greater than 3 s for porous long type.
