Before we go off into an alternate universe, let's go back to basics. Primary voltage can and will affect secondary voltage, afterall it is what produces the secondary side of the circuit to fire the plugs. BUT! secondary voltage does not and cannot affect the prmary side. The voltage problem being read is not a reaction of bad wires or plugs feeding back to the primary side of the coil. It's not withstanding that these items are not causing the miss or poor run conditions. It's just that plugs and plug wires do not make primary voltage functions do what these readings are doing.