Mercedes C220 Diesel wont start in a morning,,?

Hi.
I have a mercedes C220 Diesel !994/95 and when i get into it in a morning i have trouble starting it.. Here's what happens. the engine fires up no problem first time' Then the it cuts out after about 12 seconds ' then i start it again and the engine kinda revs up itself then cuts out. and i start it again and the engine runs fine as if nothing happened to it it is ok all day then. any ideas.
Kind regards
Stoddy2k01.