Don-
My 55 Imp with four barrel does the same thing. If allowed to sit for a few
days I have to prime the carb to start it or crank forever. Easier to prime, as
it starts immediately.
causes could include a leaky needle valve that allows the gas to drain into
the manifold after shut off, or a cracked carb casting which will do the same
thing. Until the carb fuel reservoir fills again the car is a no start
I don't think the fuel pump check valve would do it as there should be
enough fuel in the carb reservoir to start it. The only way you can verify the
lack of fuel in the reservoir is to remove the top part of the carb and check
visually.
I have heard of heat soak forcing the gas out of the carb into the manifold
after shut off also-
good luck let us know what you
find
Ted