Car will start only when gas is poured into the carburetor and then immediately stops.
There may be a little screen filter inside the fitting where gas enters the carburetor, might have got plugged. The needle valve just inside the carb whereby the float controls the entrance of gas, may have got stuck in its seat. Or the seat, where gas enters the carb., may have something lodged there.If you are pretty sure the pump's volume and pressure is correct, (it would be low pressure, like around 5 lbs., and you check volume by timing how long it takes to fill a specified amount-sorry, I don't know or remember any specs anymore- but anyway, you must have taken the line off at carb to check for gas to carb-if it squirted out at a good clip when it was cranked over, it likely passed the test-hows that for accuracy? lol.), but as I was going to say, if you have gas to carb., and no amount of pumping the throttle lets any gas through, you will want to take the carburetor off and have a minor rebuild kit installed, just all new gaskets and seals, rubber or leather parts that get old and leaky, new needle valve and seat.If you want to just check the bowl inside for gas in it, and the needle valve, too-it can get pretty tricky, but you could take off the top of the carburetor, called the air horn, held by its several screws, and tricky because you have to unhook the choke rod, maybe anything else for getting the top off...If you take it off, you will want a new gasket there...I recommend just taking the carburetor off. Has this car ever sat for a long time? The carb. would need a good and thorough cleaning of every little passage to bring it back to like new condition..Good luck. It might be something simple, like a bad needle valve, or a filter, wow, what a slam dunk that would be. Wouldn't even have to pull the carb off.