How about your primary
fuel filter? Have you replaced its cartridge lately?
As for your tank, I've heard of others temporarily running from a
line into a different tank for pick-up, to see if the suction and inline filter stays filled. You can imagine the necessary safety precautions to do this, however.
Last question: how old is your electric
pump? I'm thinking of replacing my mechanical with an elec from Moyer...
Jim H