Fuel pressure regulator

[pat]

It looks as if the fuel pressure isn't high enough. If you connect it to the P2000, you can read the fuel pressure while starting and running. If this pressure is ok (which I don't believe), the fault isn't in the fuel system.
If the pressure is not high enough, it also can be following issues
- I had some issues with the pump in the tank. If you can hear it run, still the flow of this pump can be too low. You can messure the fuel pressure in the low pressure system (between fuel filter and HP pump), it must be around 2,5 - 3 bars. If you measure this, and it stays whilest running, the tank pump is ok.
- The pressure regulater on the HP pump has 2 little O-rings, they can be broken or worn as well. Just take the pressure regulater off (2 torx bolts I believe) and check the 2 little O-rings for signs of wear or damage. If you have a second regulator you can just swap them and try if this solves your problem.
- It can also be the rail pressure sensor (doesn't happen a lot). Take of the connector from the sensor on the middel of the high pressure rail. Try running with a disconnected rail pressure sensor, if it runs fine now, this sensor has failed.

[Welly]

sounds like good advice to me.