Mounted to the engine block on the inlet side,just above the level of the sump/block joint.
Wasted spark ignition system consists of two high ratio transformers whose secondary windings are connected in series to plugs on cylinders 1 and 4 or 2 and 3. The primaries are connected between a MFRU controlled +12Vdc and ECU.
As with all ignition systems the idea is to cause a spark of correct duration and timing to occur on the firing stroke. In a wasted spark (or Distributorless) ignition system, the ECU will control the timing of the spark based on a “MAP” or look up table which is effected by engine load, RPM etc.The ECU will switch or ground one side of the transformer primary causing a high voltage level to occur at the secondary winding. The secondary winding has two spark plugs connected in series across its outputs and a spark will occur on both plugs simultaneously (practically). As the plugs are “paired” in cylinders 1-4 and 2-3, one spark will cause ignition to occur on one cylinder in its firing cycle, the other will be “wasted” as it occurs at the end of the exhaust stroke of the non firing cylinder.
|1|| ||ECU Controlled +12V out to Spark 1||DC||Spark Plug Con. 1 Pin 1|
|3|| ||ECU Control Spark Trigger (GND Sw.)||DC||ECU(Black) Pin 25|