Does your model have the NATS ? I'm just thinking out loud here, but when NATS stuffs up sometimes it locks the injection pump out on the 4.2TDi's. Now I don't know if the same NATS principle is applied to the 3L Di's, but maybe, just maybe... What is the little red light on top of your dash doing ?
Edit:
The other thing could be air in fuel system ?
The injection pump especially VP44 without supply lift pump has real difficulty to supply and also prime injection lines at engine cranking speed especially when there is an airlock.