Hi all, the other week my 2013 320d M Sport (F30, N47) came to a cough and splutter like I’d completely stalled from being at cruise control on the motorway. Pulled onto the hard shoulder and knocked her off. Tried the classic on and off, to get a engine cranking over with what sounded like good compression but no start. at the time of the fault the dash brought up “drivetrain error, possible to continue journey”. After a quick fuse check we got recovered and dropped off at my dads garage. Being an ex HGV mechanic I thought I might as well have a punt at some stuff. Connected a snap on solus that I borrowed from a neighbour to find only 1 fault being 249300, rail pressure monitoring on engine starting, rail pressure too low. I started from the tank onwards. LPFP running feeding 4.4 bar when cranking. Changed the fuel filter next just as precaution(only changed 4 months ago) and to no surprise still the same situation. I pulled the data up from the diagnostics, actual rail pressure builds no higher than 97 bar, and on cranking just read between 50-97 and fluctuates. Took the rail sensor off and checked for any swarf to see nothing and pulled the metering solenoid valve off the HPFP to check for any swarf in the gauze to which there was nothing. Put it all back together, primed and bled up to no start. changed the pressure sensor to be sure, still no start. Bit the bullet and just bought a new HPFP got it all changed, primed and bled up the rail. Exact same problem and exact same rail pressure fluctuation. 800 quid down the pan unless I can sneaky return it. Just wondering where to go next. done a leak off test and injectors are good on that side of things and timings bob on as cam followers are moving when moseying through the filler cap.
about Exhausted my options. Rail pressure regulator on the back of the engine stuck open maybe? hesitant to take it off as someone mentioned it’s programmed and coded to change whether that’s true or not. Has anyone got any voltages to try backprobe some plugs? Or any hidden fuses or relays I should know about? Took the back seat out to look at the ”relay“ on the door stay/pillar to just find a sealed box(which in fairness controls the LPFP”.
Thanks for any help, patience is slowly running out but just glad it’s not sat racking up a labour bill at a garage somewhere.
about Exhausted my options. Rail pressure regulator on the back of the engine stuck open maybe? hesitant to take it off as someone mentioned it’s programmed and coded to change whether that’s true or not. Has anyone got any voltages to try backprobe some plugs? Or any hidden fuses or relays I should know about? Took the back seat out to look at the ”relay“ on the door stay/pillar to just find a sealed box(which in fairness controls the LPFP”.
Thanks for any help, patience is slowly running out but just glad it’s not sat racking up a labour bill at a garage somewhere.