225 popping out the exhaust, but...

The other day,.well for the last few times out with the car the engine just dies and or sputters while driving and pops out the exhaust and I mean loud. Even when I start it cold this happens sometimes. Then I'll crank it and crank it and pow out the exhaust. It's like the fuel is still getting to the cylinders and then the ignition just turns on again. I'm thinking ignition issue? It's got points still.
If it doesn't do it when cold, then I suggest a hot compression test, maybe it's time for a valve adjustment, and then a fresh compression test.

Oh wait, I reread your post and it says also cold.

A cracked plug insulator can do a similar thing, until it fails to spark at all.