4-SP. 8.3 LITER. 4 Leads. An induction Coil, placed on each sparkPlug of a vehicle and used with and ECU and a Camshaft or Crankshaft position sensor for timing, to transform a vehicles battery voltage to a much higher voltage needed to create proper spark in the spark Plug. An induction Coil, used with a distributor for timing, to transform a vehicles battery voltage to a much higher voltage needed to create proper spark for all spark Plugs of an engine.