Here's my experience:

http://www.peachparts.com/shopforum/showthread.php?t=155624&highlight=fuel+pump+relay+jumpered

Same issue and the fuel pump relay was the cause. You can resolder yours and make it good again. In my case the PO had done it years ago and it finally let go once again, so I just broke down and bought a new one from Phil.

__________________
08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280