Got a Gremlin

IDK what to think about this car. Every now and then it'll start right up, run for a minute or two (sometimes a matter of seconds), and suddenly die. When this happens, it WILL NOT crank back up. I smell gas when I'm trying to pump it to make it crank back up, so I know it's getting fuel. There is a brand new coil, brand new wires, cap & rotor, and plugs, so ignition is unlikely (although the way it just DIES...with no sputtering or hesitation at all suggests it is). It runs GREAT when it decides to, so I know I don't have a compression issue.

Occassionally, this will happen when I'm driving also. Running great one second...dead the next.

In every instance, it will crank back up whenever it damn well feels like it. Sometimes it's a matter of two minutes...sometimes a matter of two hours.

Could I have gotten a defective coil? It IS an Autozone coil, after all. Is it maybe overheating and cutting out until it's cooled down? If so, how can I explain the times I'll run it 150 miles without incident?

I also put on a new 600 cfm Summit Racing carburetor at the same time I put in the new ignition pieces. Could this intermittent, sudden death be caused by the new carb?

Or is there maybe a relay that is wearing down somewhere?

Please help!