Check to make sure the fuel pump runs while you crank -- if it is going bad, you may not get enough fuel. Just pumping fuel with no real pressure won't work -- fuel pressure has to be something like 40 psi for the injectors to open. Dirty fuel filter will cause this too.
You can also gently press down on the mass flow sensor flap while cranking, this will deliver more fuel -- have a care, you can damage the fuel distributor.
You might also pull the cap and see what condition it and the rotor are in -- the rotors have been known to fail, and it if is well off center, the spark could be going to the wrong cyinder. Not likely if you cannot smell gas on the plugs, though.
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!