could it be the fuel pump relay or the ovp?
Not sure if they have anything to do with your problem, but it sounds really strange to me, and I am interested in finding out what it is, because I haven't heard of this happening before...
Another thought I have is that mabe the fuel cap is not sealing correctly, letting air into the system, so maybe at low tank, air is getting sucked in? Just a theory though, I really have no basis for it other than a brainstorm.
Good luck on finding out what is wrong. keep us posted.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.