renault traffic- stalls whilst driving, lose all power. ?

02 common rail renault traffic; the van stalls whilst im driving at any speed and has almost become un-drivable, i lose all power. but i can re-bump the car almost instantly and carry on driving for a bit, then it will stall again and again.... i have had a diagnostic done and it said it was either the four injectors or the high pressure fuel pump.
If you have any other suggestion, as to what might be the cause i would be very greatful.