fuel pump/smart valves

[rcaustin]

On my 2008 M8 turbo, when I started getting low on fuel I start to lose fuel pressure... aka the smart valves aren't closing when they sense they are sucking air... is this common when running an auxillary fuel pump? sucks to much fuel so the valves can't close in time? or is there an issue with my smart valves. The problem with this is when i say my fuel tank is getting low... there is really still 3-4" left in my tank... so when it starts to suck air like that I have to fill up again so im not losing fuel pressure... This converts to me hauling 7.5 gal of extra fuel up to the cabin = pain in the you know what.

Anybody experience this or have reccomendations to solve my smart valve problem if that is indeed what the problem is? Just buy new smart valves? are they pricey?

Thanks in advance,
Ryan