hello, i still need assistance from one of your experts... thankyou.
Hi there, sorry for your wait.
are you saying the service engine light comes on when you try to accelerate and the van cuts out on you?
If so it's likely storing a fault code which could be very helpful.
If the rail pressure sensor is detecting a pressure drop and pressure valve operation dropping off it should throw a fault which would save in diagnosis time.
More commonly these symptoms are relate to the suction valve on the side of the pump and not a fault of the pump itself. These valves control pump volumes and if they are not functioning properly the rail pressures will be off and you will get fuel cut.
Let me know how else i can help. thank you