Sounds to me like you have a slight air leak in the fuel system. Next time it dies take a look at the clear pre-filter...I bet it will have air in it. Try tightening all of the hose clamps and bolts on the fuel lines and fuel filter, and if possible replace the crush washers under the "banjo" fittings.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine