240D white smoke and no power

[955405]

I have a 1977 mercedes 240D i just recently bought. i changed all the oil and all the filters. The car was running fine for the first several weeks. i started out to cincinnati Oh and topped off the tank at wal-mart. about 40 miles later i was getting a cloud of white smoke behind and had no power (out of the ordinary). I then changed the fuel filter think i had got water. A few hours later we had it towed home. Can somebody give me some advise i was told to check the timing on the injector pump and the cam but the owners manuel doesnt advise on this.