sudden stops

[D Daniel]

My 91 100Q  (110K miles) has developed an annoying problem.  The engine 
will quit suddenly without warning!  After a great trip to Monterey it 
quit about 30 miles from our house during a 100 mile trip home after 
running flawlessly previously.  It then continued to die periodically 
during the last 30 miles.  Always would re start quickly but this 
happened 6 or 8 times towards the end of the trip.
New plugs, new rotor & cap.  New coil & fuel filter.  Had previously 
behaved this way and was hoping the fuel filter and/or coil would fix 
it.
Runs great. Passed smog no problems 6 months back.  Fuel pump?
Any thoughts appreciated.  Thanks, Don