Strange Ignition problem w/ '83 4000q

[Stott Hare <qa3@bur.dmcc.com>]

Greetings,
   This is an interesting one for the net.  A friend of mine had his 4000q 
refuse to start
Christmas day.  The result of initial diagnostics was no spark at the plugs. 
 The rotor
was turning, so no broken timing belt.  The coil ohmed out within spec.  Now 
here is
the interesting part:  the spark makes it through the coil wire to the 
distributor, but is
stopped there somehow.  No spark is seen by the spark plug wires.  A new cap 
and
rotor were thrown on for good measure, but still no spark to the plug wires.
   One piece within the distributor was found to be broken.  If you were to 
begin
disassembling the distributor, you would take off the cap/static shield. 
 Then the rotor.
Beneath the rotor, there is a black/gray plastic (dust shield?, static 
shield?) circular
piece that covers the hall sensor parts inside the dist.  This isn't 
fastened down by
any means other than a tab matching a notch in the dist. case and the 
pressure from
cap and rotor.  The broken piece is off of this circular plastic part.  The 
tab that fits
into the dist. body notch has broken off.
    So with this info, can any glint of a solution be seen?  Is this strange 
black plastic
circular piece serving some mysterious position sensing function that the 
Hall sensor
needs?  Is this broken piece at all relevant or just another piece of junk 
for the garage
floor? Any help would be most appreciated.

Thanks
Stott - A VW owner and closet Audi freak