1982 mercedes 300d acting like out of fuel

[craydemm]

I just bought a 1982 mercedes 300d turbo diesel that ran well for couple days then it acted like it was out of fuel. a couple days later it started up just fine and ran about 2 miles on the highway and done it again. The engine will catch and run for another minute longer if I put the tranny in neutral and rev the engine up (It spits and sputters like its out of gas then levels out smooth again) but a minute later running under a load or in slower rpm's it dies. Starts up fine when it's cold.

Anyone have any idea as to what's wrong with this car? Even advice on how to diagnose the problem would be appreciated...