Weird sputtering issue

Thanks everyone, I'll try these things tomorrow... Speaking of the coil,
I posted this earlier on another post:

Maybe one of you knows the answer to this...

Years ago, a good friend of our family showed me how to "ground the coil"
on my 65 Barracuda to serve as a poor mans anti theft device. He helped me rig a switch hidden under the dash with a wire going through the firewall to the coil. If the switch is not "on" the car will not start. I can't remember if the wire went to the positive or the negative side on the coil. I think the other wire from the switch went to ground.