Your list admin here,
My new engine ('84 Vanagon) is great when it runs well, but it doesn't
always do so.  It seems that as soon as it warms up, it starts running
rich.  My clues as to the rich running are black smoke out the exhaust and
black deposits on the spark plugs.   The running symptoms are that it
misses and feels like it's running on 2 or three cylinders. Mechanically
it sounds really good.
  Things I've swapped and checked:
      Oxygen Sensor
      Temperature Sensor II
      Temperature Sensor I (statically -- it may not be moving right, but
                            on the other hand I swapped the entire...
      Air Flow Meter
      ECU
      Grounds -- all sparkling clean and tightened down.
      Full throttle and idle switches -- working perfectly.
  Yet to do (will get to VERY soon):
      Fuel Pressure Regulator (the one in there is pretty new)
      Vacuum (would this cause a rich condition?)

Because all of the spark plugs are fouled, I doubted a problem with the
injectors unless both sides were hosed.  This engine was sitting for over
a month, so that could have something to do with it. 

If anyone has other clues of things that I need to look at could you
please respond quickly?  I'm running out of beer-type consolation.
Thanks!
--
Gerry
Gerald Skerbitz <gsker@med.umn.edu> U of MN Med School Admin 6-5379
Home St. Paul,Ramsey County,Minnesota, USA