I was told that Bosch injectors were matched at the factory to within 7 bars. I know that custom Injectors are held to a closer tolerance. Has anyone ran a set of 275's that the pop offs were adjusted to a tighter tolerance? Was there a improvement from before and after? And what was the improvement in your opinion?

 

Your right. Bosch is very tight in pop pressure tolerance. Almost all new injectors test within a couple of bar or less. The biggest trouble is they creep downward very fast. Stock they should test 305, but I get them over here constantly that go 250-260.

Pop pressure within 20 bar is not a big deal in a Cummins as long as it is not too high. Over 305 bar seems to cause trouble in worn out or weak VP 44 pumps.

If you have new 275's or slightly used ones....your chances are good everything is fine.

Don~

 

Thanks Don for your answer.
What do you think the reason for the creep down? I was just wanting to make sure that all six injectors were running consistant with each other to keep a smooth running engine.

 

Wear of the needle in the nozzle body and spring fatigue.

Don~