Fred,

When you remove the filler cap on the tank, does it seem like you have a vacuum? I know that sometimes the tank vent clogs and as you use fuel the system goes below atmospheric pressure. This can collapse portions of the tank, and it will eventually shut the car down.

The fix in my experience was to replace the soft rubber connections as they had become gummy over time and just got kind of glued together on the inside. Good luck, and I hope this helps, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)