Could be a weak starter motor or even a tired battery. If thats not it get the injector leak backs checked. Also if the vehicle creates enough rail pressure at cranking?
Try finding your nearest diesel specialist to carry out the Diag.
Scott
February 2010
have you tried to see if the heater plugs are getting any power if they are not try fuses to see if they are blown if they are not it might be your relay.
wayne
October 2009
I think I'd be checking out the electric fuel pump in the tank first...they are known to fail.