This sounds like interference generated by the HT system that supplies the spark. If you find an equivalent resistor plug (thats a plug with a resistor built in) it will work fine. Alternatively, fit a resistor plug lead, much like the ones in your car. Remember when AM car radios used to pop and splutter every time another car went by? When resistive HT leads became normal, that problem went away.
Fitting a 2.4GHz set MIGHT work, but I see you losing all your friends still using 27MHz AM unless you suppress you HT system.