Hi guys,
looking for some pointers about low fuel pressure non starter.

Its a 1.9 cdti 150 16v.
Originally the car had high fuel pressure and the ecu kicked in and stopped it from starting. It was cured with a replacement fuel metering valve on the back of the high pressure pump.

Now im wondering if the high fuel pressure problem has damaged or blew off a pressure release valve inside the pump.

Ive replaced a few parts including fuel rail and sensor, another fuel metering valve, fuel filter and also changed the intank pump.
The only parts left to change in the fuel system are high pressure pump and injectors.
I have got a leak off tester but I doubt it would prove much as I believe the injectors need a fair bit pressure before they work.
Do you think the High pressure pump could be the likely fault as said diagnostic scanner shows no rail pressure when cranking.