have you checked the pressure relief valve isn't stuck open ,hence you can't build up pressure...
though i do DAF it's the same engine with 1 or 2 minor differences ,..my general approach ,is to check what the volts drop to on the batteries whilst cranking the engine and to watch the rail pressure,as to high a voltage drop and the ecu shuts down ,and if you can't get to a pre determined rail pressure then it won't start .next i check the torque of the gland nuts on the injector tubes ,should be 50nm ,if slack then fuel leaks by and can corrode the ends of the tubes cutting fine grooves in them...next i disconnect the metal fuel feed pipe to the rail have someone spin the engine and see if i am getting any fuel .if not, check for either blockages / leaks back to the tank ,or the lift pump bolted to the main fuel pump shears it's drive..if fuel is being delivered ,then i carry out the fuel leak off test ..as said earlier as each injector is disconected from the fuel supply you should get less than 30ml...
a quick check of the pump is to disconnect the electrical plug from the prop valve ,which will then deliver max pressure to the common rail and will on the DAF anyway give a red engine warning and the engine runs rough ,re connecting the plug clears the warning and any rough running
norb, December 2011