Check the rotor inside the distributor and the dist cap for cracks, carbon build up etc. if everything checks OK, check for power at the coil with the switch on, got power, Pull the coil wire from the distributor and hold it about 1/2" from the hole and have somebody turn the engine over, do not touch the end of the wire, no spark = bad coil, got spark, pull a plug wire at the distributor, "not the sparkplug " hold it 1/2" from the hole and turn the engine over, not spark= bad rotor or condenser.
hope this helps.