AlexNo

Hello, i recently got a drivetrain warning when driving from work but the behaviour of the car did not change so i deleted the code and drove home and it did not come back and car felt normal, but when i came to check it next morning it will not start only cranks i also got a code for "rail pressure too low"

This is where i am lost as i opened the rail and no metal shavings, i also removed the sensor on the HPFP and no shavings there either i have also had the LPFP out and it looks normal and pushes 4.5 bar when tested with ISTA,
i have already changed the fuel filter and bled it and no changes, so what i think is maybe one of the rail sensors or the sensor on the hpfp is bad but will this cause it to not start?? and can the HPFP be broken even tough there is no shavings in the system or pump? and if none of the above what can cause this?

(EDIT) i have now changed the quantity control valve on the hpfp and the valve and sensor on the rail and no changes

Car is a 2012 530d n57 car has gone 136k KM or 84k miles
the car has been tuned but this was well over a year ago and 10k km

I appreciate any help as car is needed

Seth dustin

Did you check the fuel injectors ?

seanjordan20

What are the HPFP pressures. You can tell if they are bad by the pressures. Run the fuel tests available in ISTA to help troubleshoot. Many tests you can perform to test the injectors and pumps along with spark plugs and coils

AlexNo

I do not have any of the tools needed to check the injectors yet but might have to get it, what i find weird is when i take the rail of it is almost empty would injector problems not let the fuel get up in the rail still?

AlexNo

When i test for pressure while operating the starter it reads 2.2 bar the setpoint is supposed to be 250 bar+ , one of the other test where it says 0 +/- 26 bar it also reads around 2 bar