My '73 D-Jet w/Pertronix started acting up today. After about 10 miles it began stuttering above 4k RPM rpm on the freeway, so I first I thought it was the same problem as last time, fuel filter and/or pump.

But it never died out, but it did get worse over rough pavement, so I continued on and made it all the way to my friend's shop.

I checked for loose connections on each spark plug wire, the injector connections, the coil, the trigger points on the dizzy, the MPS & CHT wires, and fuel pump connections, and the Vacuum advance hose.

One thing that did seem odd is that when I wiggled the Pertronix I could move it (and the advance plate it is attached to) vertically about an 1/8 inch. That didn't seem right.

Later test drives with moderate throttle reveal a low RPM stumble, like it is too rich, clear running from 2 - 3 kRPM and then more suttering above 3 kRPM. Steady-state throttle was better, but not confidence inspiring enough to drive the car back home.

Help?

Thanks in advance.
Mark

the pertronix is usually on/off, meaning if it brakes, it will stop working altogether.
one thing to check, i had the wires on the pertronix hit the rotor shaft once and the shaft wore the rubber insulation down until the wires shorted out. you might wanna double check.

as for the plate moving, if you have the stock vacuum advance dizzy, that plate is supposed to move ...
Andy