[ossiblue]

Just a guess, but I'd lean toward an electrical issue. Ten minutes of idle gives time for components to heat up and resistance to increase. Failure to start until after a long time passes allows for cooling. Next time a failure happens, run a check of the spark by using a spare plug attached to a lead and grounded to the engine. If spark is strong, move to fuel delivery.

From your signature, it appears you have a '75. Fuel pump should run with ignition in ON position. If it were my situation, I'd eliminate the fuel delivery issue by checking pressures and function of fuel pump. Unless altered, your fuel pump is located above the left rear axle, close to the heat of the engine, another suspected element. If the pump and pressures checks out, go the ignition route.

Does the fuel pump continue to run after the engine dies?

What type of CDI/coil do you have?