Thanks for the replies I've got privately with this matter.  All refered to
an electrical problem in the ignition circuit.  Well, it happened this
morning to me on the way to work, it was raining.  I was mistaken when I
first said it was running on 2 cylinders.  While it was puttering this time
I ran around back and hooked my timing light to each spark plug and observed
all 4 sparking, they still sparked when I'd opened the throttle, but still
the idle didn't respond to throttle - just sat there putting.  Blackish
smoke did come out the exhaust with the throttle open, but idle didn't
increase, it just rumbled.   The engine has less than 5000 miles on it.  The
idle would slightly change when I pulled any spark plug wire.  After a few
minutes the engine came back alive and I drove the rest of the way to work
with the engine hatch off, but this gave me no more clues.  Any advice?

Thanks!
Christopher
81 westfalia