Swapping feed and return lines as per Bio... is a good idea, as is making your own fuel tank to isolate a potential problem as per Bio... again. The primers are old, and many leak and fail. Running bio diesel will speed up this problem, as it is corrosive to rubber and the internals don't last long. I've had five MBZ, have replaced all with the black unit, use old style for bio, it'll last a bit longer. Fuel pump failures are rare, yet not unheard of. But if you can't pull fuel from tank, doubt that's your problem. Clogged tank strainer more than likely, perform above tests, go from there. Good luck. Oh, and if Iraq is experiencing a civil war, we, by definition can't be involved, Steven Colbert.

__________________
83 SD

84 CD