motor run motor start.

You know, after thinking about this for a min I think it's either no signal from the distributor, or an ignition module.
The pop when the key is turned off usually means the coil is getting power and when the key is turned off the coil field drops and you get one spark firing whatever fuel is available in the cylinder the rotor is pointing at when the coil fires that one spark.

Might be time for some specifics on what coil and distributor exactly, so we can see the wiring layout needed for what is being used.