Sounds to me like the coil may be hooked up wrong. There's only supposed to be about 9 volts going through that resister wire. It is used on all 12 volt cars with
points to drop the voltage to protect the points during starting. I'm not familiar with the Mallory e-Spark. If you are not running points any longer you will want 12 volts going from the ignition switch to the coil. That can be done by adding the 12 volt wire or by using a relay which would be opened by the resister wire to pick up a 12 volt source. I hope that's some help.