Would a bad ignition coil cause a car to do this?

Run for 20 minutes or so, then die without any apparent reason? Allow the car to start and run for a few seconds, then die and not restart? Refuse to start at all?

Care to name the car? Some cars may be good bets and some not so good for doing this. Some other part does that too.

1984 Peugeot 505 with 4 cyl gas motor. It seems to have good fuel pressure and gets air fine, so I’m down to spark (which is missing right now at the distributor).

It could. You should also verify that you’re actually getting power provided to the coil from the ignition switch. A faulty switch (electrical part) could cause a crank/no spark condition.