In the daily life,if you drive your car to the repair shop and describe that your engine is suffering from poor power,black smoke and high fuel consumption.The maintenance worker will usually check your injector firstly.After the injector is disassembled, the pressure is tested on the nozzle tester.As long as poor atomization is seen,they will judge to change the nozzle.But actually after that,the problem is still there.So this is the misjudgment that often appears in maintenance.
How to check whether the injector needs to be replaced or not?
For injectors, the opening pressure will decrease after a period of using.But the pressure of original BASCOLIN brand injector
could be assured within 20bar which has no effect on the performance of diesel engine.
It's not standard or right to judge only from the nozzle tester.For injectors from genuine BASCOLIN or BOSCH, it's tested on the special DPS test bench to check the injector seal, vibration jump, open pressure and other characteristics, when all of these parameter have reached the requirements, it will be qualified finally.
Therefore, we occasionally find that the injector tested by the DPS test bench fails to pass the manual pump nozzle tester inspection.It shows bad atomization. However, this situation will not affect the performance, because DPS simulates the actual working state of the injector, while the manual nozzle tester can only check the opening condition under low pressure.
In aftersale service, if the injector appears the following situations,it means your engine performance will be affected : no pressure or very low pressure, serious oil dripping, no oil spraying and oil leakage.
If it's only the phenomenon of poor atomization without serious oil dripping,you could try to replace the injector with another cylinder that works well, rather than simply replacing the nozzle.
Of course, if you suspect that all injectors in a diesel engine are unusable, it's better to prove it with a injector in reserve, or don't replace it easily.