low fuel pressure traffic 03 1.9dci?

help,
my van wont go over 3000revs when stood and wont go over 4 when moving it then cuts out when i put my foot down i drives but its a pain it must do it evey 100m or so, i've had it on a diog machine the fault is fuel presure its normal on tick over 260psi the problem is when moving its not the injectors had them done its not the high pressure fule pump had that done i've also had a new wiring loom fitted what could it be i've had enough of this efin van ;(