Turn the key to the on position , Can you hear the electric pump running ? Disconnect the line between the mechanical pump and the electric , Get something to catch the fuel , Turn the key to the on position see if any fuel runs at the outlet side of the pump. Should be a steady flow ! To degunk your tank , First, Drain the tank, remove the hood, grill and side panels. Then pull the sending unit out of the tank , Be careful not to wreck the gasket under it or any wiring. Then I removed the lines and tank. I fashioned a giant Q - Tip ( steel rod, rags, and duct tape ) to swab out any gunk in the tank and rinse with clean fuel. Then clean the brass screen on the sending unit mine was packed. Now reinstall.