Having the engine on my ’91 Bronco suddenly die while rolling along the interstate at 70 mph with big rigs and cars all around is one of the most unnerving situations I’ve been in, on or off-road.

Ignition systems can be one of three basic designs: the distributor ignition system, the distributorless (DIS) ignition system or the coil-on-plug (COP) system. They all perform the same function, but ...