Fluctuating neg. to ground on ignition coil

512Stroker said
OP have checked to see if you have not wiped out a cam lobe on the engine?

Wouldn't that show up in the compression test or create vibrations at other RPMs than idle as well?

If not, how do I check if a cam lobe is wiped out, removing the valve cover to see if all rocker arms move in a similar way?