[Early_S_Man]

Bad or intermittent grounds can cause the Bosch or Perma-Tune units to have a weak output, or intermittent output that is OK on some firing pulses and non-existant on others ... simulating a misfiring fouled spark plug.

If the Perma-Tune unit is damaged ... it would most likely be permanently dead, and not intermittent.

There are braided groung/shield cables between the distributor and CDI-unit, and between the CdI-unit and coil, so is it one of those you say is bad, or is it the body-to-transaxle mount strap you found bad?

Instead of depending on the Perma-Tune/CDI-unit box to M6 bolt to the relay panel, and relay panel to body ground connection ... I like to run a ground strap from the CDI-unit to body directly.