Hi.
0087 Diesel high pressure regulation circuit pressure below reference value
0093 Diesel high pressure regulation circuit pressure below setting and pump filling flow setting too high.

When driven hard on the open road this engine dies.Fault codes point to fuel pressure faults so I scoped rail pressure sensor. The rail sensor maxes out at 3.1v (1100/1200 Bar). On live data you can see a 100 to 150 Bar difference between desired and actual pressures. Did a leak off test on the injectors. All were even and slow to leak. I hooked up my WPS to the fuel supply. I am getting -62 mbar at full revs or -50 mbar at idle. I clamped the pipe and the pressure went up to -500 mbar. I cant find specs for this car but from a similar car these figures look good.
Thinking it was the high pressure pump I shorted out the IMV valve. The fuel pressure went straight to 4.8v (1800 bar). This proves the pumps ability to produce the required pressure and the rails ability to hold the pressure.
I have run out of ideas.
If anyone has any more ideas or can think of something I haven't checked I would be grateful for your views.
Sorry about the essay.
Thanks.
Fiachra