Hi everyone,
i have a w208 with a constant prolem ie it cuts out , turns out that the scavange pump, the pump from underneath the tank draws air inside fuel system and it looses the fuel pressure and engine dies!!

However there is around 25 litres of petrol inside fuel tank and it appears that, driver side tank is constantly empty and passanger side almost always full??
if i put 5litres of petrol engine will run for 5minutes until return pipe from petrol filter throws all fuel from driver side tank to passanger???

I have been told there is an internal fuel pump that returns fuel from passanger side. I have pulled both sides-fuel tank senders out and i couldnt see any internal pump to returne fuel to driver side tank???

i would very much appreciate if someone could help me out !!!!

senders are under tank , does anyone know of any common problems , sensors seem to work ok .
Many thanks in