Most likely air in the fuel system. You should bleed it completely (work the hand pump until you hear fuel hissing in the return line). This will take quite a while if the fuel filter is empty.
Also, check for a leaking fuel line from the tank to the hand pump, or for a leaking hand pump. Either one will allow air to get sucked in rather than fuel, result being air in the injection pump and no fuel delivery.
Check all the postings in the diesel forum on this issue -- you should find lots of advice there!
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!