Random cranking issue, M57 diesel 2003

[wpoll]

Originally Posted by Clavurion

... Correctional values (smooth running control) tells more about the condition of injector nozzle (fuel atomisation properties).

So an injector could be leaky but the Selective Mass Adjustment values would not show that. Good to know.

[Clavurion]

Originally Posted by wpoll

So an injector could be leaky but the Selective Mass Adjustment values would not show that. Good to know.

Yes. They don't have direct correlation. The leak in this case is to leak off line, not in cylinder. There is some leak off due to working principle of common rail diesel injector. If the internal teflon seal between injector body and needle fails some of the high pressure fuel leaks to leak off side. First this will show as a slower start and eventually it can prevent engine start because required fuel pressure is not met. In some rare cases this can also stall engine on high load because of too high discrepancy between rail pressure demand and true value.

Poor correctional value will show as uneven running characteristics on idle and low RPM.





On attached picture quite typical failed teflon seal.