There is no condenser in the ignition circuit?

Any ignition circuit that I have ever touched in the past has had a condenser in parallel with the primary coil. The breakdown of the field causes a reverse EMF (i.e., voltage) which charges the capacitor. Then, true to form, the current reverses and the process repeats - a few times.

If you've ever seen an o-scope hooked to an ignition circuit, you would never again claim that the circuit was DC. It is an AC spark. The first half-wave is the strongest, yes, but it's still AC.