Originally Posted by
mattnew
If you did try this... the plug wouldn't be grounded... so you wouldn't get a spark when the engine turned over... and your right, no spark, no interference, everything would work as normal....
Incorrect, the plug is grounded if it is inserted in the plug cap. The ground return path is the shielding on the plug lead. It doesn't have to be screwed into the engine and you would get a spark at the plug.