[rv7cfglh]

Hi, i purchase from van's 6 years ago uma tach for slick mags, i replace my engine and the new one is now equip with bendix mag, the tach is connected directly on the mag p-lead with swich for reading left or right mag, since this new installation the engine is sometime missing (like bad spark plug), when the engine is missing, if i put the L-R swich to center (open ) the engine stop to miss, the tach cause really the problem,

Is anybody have experience this problem ?

Anybody have solution ?
Thanks to answer
Jean