would bad spark plug(s) lead to other electronic issues ?

[bcleveland]

My 1985 Venture Royale with 73,000 k's starting acting sluggish ..Starts up fine and idles fine for a bit then blogs down. Under load it feels sluggish and you can smell unburned gas. At same time the Tach gauge starting working intermitting . Plan on changing plugs as a first step(has new Battery). It was suggested even one bad plug can cause other electronic issues. Is this so?

[Flyinfool]

About the only other issue a bad plug can cause is static on the radios.

 

A big clue is the tach acting intermittently. The tach is driven from the primary side of the #2 ignition coil. When the tach goes out it means the #2 cylinder is not firing.

[cimmer]

I would recommending checking the coils and the TCI unit as they could be causing your issues.

 

Rick F.