Engine starves at idle after 15 mins or so. I have two fuel tanks one close and the other about 11 feet away. Both feed a Racor fuel/water separator. The engine runs fine on the close tank, but starves after time when run from the far tank. Both tanks clean, new filter and body, fuel pick up clean. Planning on running a new line to tank to determine if line is blocked. Could this be a low pressure pump issue? Engine performs perfectly otherwise.