I bought a '81 300D and it would start easily through the fall, when it started to get cold (25-32 deg F) it was still starting. I went out and tried to start it when the temp had dropped into the 20's and I have not been able to start it since (even now that it is summer time). I have checked the glow plugs, I replaced the priming pump and fuel filter. I have loosened the fuel lines at the injectors and I am not getting much fuel squirting out when I crank the engine.
I have bought the compression tester, and tools to do a valve adjustment, but I have not done that yet as I don't think that is the problem.
Is there another fuel pump at the tank that might have a blown fuse or something else?