For search purposes.....
My injectors are retained in the rail by a clip so dead easy to check. All OK. Given FPR and injectors all OK pump was top of the list. Cut the access hatch bigger in the VX to get the pump out rather than drop the tank. Problem solved! What was really noticable was the note of the pump. Old pump sounds deep, new pump is high pitched. What I also noticed is how small the pump part of the unit is. No wonder these things fail, its puny!