N47 not starting no fuel pressure

[NitroRules]

Hi everyone I'm new to the group my wife bought 2012 x1 2.0d n47 motor serviced it it in feb 2 weeks later oil level light started coming on checked oil with dipsstick was on its mark replaced it next weekend with a working second hand one oil light fine 9 days later on her way home car engine light came on and engine died its now a mounth later still no start cranks but nothing else .

Two auto electricians no faults
Changed itms so far
Injectors (was coded)
3 high pressure fuel pumps
Rail pressure sensor
Rail pressure regulator
Cam sensor
Crank sensor
Volume regulator
Low pressure fuel pump
Fuel filter
Swapped cas ecu and key with wrking one
Intake manifold with throttle valve

Still no start only with easy start it runs but fuel nock is heard and engine dies and backfires thru intake then just cranks again

Also checked cam chains and timming found everything spot on

Any help please

 

[Gordvisr]

have not worked on any of these cars yet but had similar issue on a different car but have a look at this.
Is there a pump inside the tank ? If yes, next Question, Does it have a pipe inside the tank from pump to a connection point ? If yes, check that pipe, put some pressure on it and see if it leaks, I had this problem on a car, replaced a ton of stuff two different pumps just to find that pipe was leaking fuel back into the tank, if it makes sense.

 

[NitroRules]

Hi found the problem it was th one of 2 non return valves inside the hpfp that was stick in open position. I blew intothe the pressure fromthe reverse side and car started first time

 

[Gordvisr]

Glad you found the problem

 

[[email protected]]

Hi found the problem it was th one of 2 non return valves inside the hpfp that was stick in open position. I blew intothe the pressure fromthe reverse side and car started first time

Hi Can you dhare the pictures of how the non return valves look , I have the same problem

 

[NitroRules]

Hi Can you dhare the pictures of how the non return valves look , I have the same problem

 

[theo19]

Hi there I've got the same problem on n47 diesel can you please send the picture of the none return valve

 

[NitroRules]

Hi in google images search cp4-1 pump exploded view its where your hp fuel line conects

 

[theo19]

Hi in google images search cp4-1 pump exploded view its where your hp fuel line conects

Thank you