I don't know a whole lot about it. thanks.
back to the VR pick up. it sounds a lot like the pulser coil.
Variable Reluctor Pick-up
The Variable Reluctor (VR) sensor is an induction type sensor, it is "passive", i.e. it does not require a power source, and has a small magnet built in.
The sensor uses a magnetic pickup to produce a signal. A core of steel is wrapped with hundreds of turns of fine wire at one end. A small magnet is attached to the other end, and this assembly is mounted in the distributor facing the distributor shaft. When a notch, pin, teeth or hole in a timing wheel (the reluctor) moves past the sensor, it causes a change in the magnetic flux field around the sensor. As the teeth of the reluctor approach the coil assembly, the flux from the magnet is pulled in close to the bar. The sudden field change induces an electrical current in the coil, which is then converted to a voltage signal by electronic circuitry in MegaSquirt-II. As the teeth move away, the flux springs back outward, inducing a voltage in the pickup coil. This induced current has reversed direction as the magnetic field returns to normal.