I'm puzzled about a problem I've been having with my 1976 240D (W115 chassis). Last weekend, I filled the tank, and drove around quite a bit in warm weather. After resting for an hour in my garage, the car only got as far as my driveway and the engine stalled and wouldn't restart...didn't seem to be getting fuel. A few days later it started fine. I had some work done this week at a shop to replace my water pump (was leaking coolant) and the car stalled again right after a warm start again. Finally it started and ran OK, so I drove right back to the shop.

The tech determined my primer pump was bad and replaced it with the upgraded style. Leaving the shop yesterday, the car stalled twice right after starting but then ran fine (should have left it there!). Drove to my friend's house and it was losing power occasionally and didn't seem like it was running quite right. After 3 hours of sitting at my friend's house, it started and then stalled again. It won't start now; it's like it's trying to catch but just can't quite. Another funny thing is that over the last few months I've noticed it starts great cold and not as great when warm.

Can't figure it out. Both fuel filters have been replaced recently and the prefilter is clear and has no air bubbles. My uneducated guesses are either the fuel tank strainer is clogged, injectors are clogged, fuel line somewhere is clogged, or perhaps it is an air issue, like the breather system? The car is kind of a restoration project as it does seem like it was pretty neglected by the former owners, and I wouldn't be surprised if some rust, dirt or algae in the fuel tank has broken loose and clogged something up. But I'm not sure how I'd go about draining a totally full fuel tank.

Any advise & suggestions would be greatly appreciated. Thanks.