C250 can't prime fuel pump

[grumpynortherner]

Hi All

I'll keep as brief as possible. 2015 C250 OM651 engine. 7 speed auto.

Timing chain rattle on start up. Inspection showed plastic guide had broken. Engine removed. Chain, tensioner and guides replaced. All refitted with no problems.

Engine cranks but will not fire. Fuel filter primed by bleeding from plastic valve on end of the 30cm hose from filter top.

Scanner shows 4 bar pressure which i assume is lift pump.

Have tried cracking off injector pipe between rail and injector and cranking, but no joy.

Since the high pressure pump is gear driven, it must be working when engine is cranking, so am i right in assuming an air lock in pump?

How do i bleed the high pressure pump?

 

[Cole@MBS]

There is a program on the star machines which allows a bleed process, it increases fuel pressure up some what!! It’s a common fault with the 651 engine!