Pat: If the plunger falls by gravity without issue, do not do anything! And yes, the plunger falls by gravity and is lifted by an energized e-unit coil assembly which turns the drum one tooth at a time.
Do not spray anything on the plunger and inner coil if you don't have to. Over many operating hours, the plunger COULD become magnetized, but I never had that happen with any of my Postwar or MPC/LTI items, so I think that is a relatively rare issue you likely will never encounter.
Does your e-unit "buzz" with power applied? If not, I'd check the solder connection on the side of the unit for a cold solder joint; also make sure the other end of the coil wire is also soldered to the frame (doing this from memory...). Some of the soldering I saw come out of MPC was sketchy at best. It should be shiny and nicely contoured, not grainy and dull in appearance.
