I had the same problem with my car. So, I'm going to suggest what my father in law told me I needed to do. I had no idea, having never owned a car older than 1984. Do you step on the gas to set the choke before you try to start the car? Without fuel injection, you need to step on the gas pedal to shoot gasoline into the carburetor in order for the car to start. I didn't know that, and kept stepping on my gas pedal trying to start the car, and wound up flooding it. You probably know this, but if you're a new, first time classic car owner, like myself, maybe this is your problem.