Car won't start sometimes..

Update? Problem solved, or.....?.If the connecting hose at the back is"cracked", the mechanical pump will begin drawing air with the fuel,eventually filling the upstream line with air. At low rpm it might work Ok, but as rpms rise it may start pulling more air than fuel. Also, hoses sometimes fail from the inside out.The pump only likes to pump liquid.Within a short time the fuel bowl(s) go dry, if running. At shutdown, there may still be fuel remaining between the carb and the pump.If the valves in the pump are not 100% some fuel may drain back towards the tank, partially draining the filter. I have also seen Gear clamps not work properly on the suction side, esp when the hose and pipe are mismatched. I try to reuse the spring clamps. But if going to gearclamps I usually put 2 clamps on;back-to-back and rotated 180* Also, If there is a restriction on the suction side of the pump, it will start to pull bubbles out of the fuel eventually starving itself. The restriction could be a failed rubber line, a pinched hardline,internal rust or a clogged in-tank sock. I have seen them all, sometimes on the same car.