In a message dated 96-09-05 19:00:25 EDT, EdBuzz@aol.com writes:

<< << Your story about hitting 85 up a grade is great! I'd love to get to
220k
 mi. on my motor! How did you "custom tune" your engine? >>
 AJ, I had been fortunate in working on cars and collecting tools since I was
 15.I worked at various German car dealers during college and the after lean
 years and have worked on cars as an independant private enterprise.In the
 ensuing years I acquired a Scope and Infrared machine(both necss. for an
 accurate tune.).When I moved from San Diego to Portland in June some thieves
 broke into my garage and stole every tool I had including all the custom
made
 ones for VW.Anyway, to set the van to euro spec, 1st disconnect o2
 sensor(digifant/digijet) and plug together  idle stabilizer(digijet).I reset
 the ign timing to approx 10 deg btdc( you need to make another mark on the
 pulley as it is not there on US versions)open the airbox and recalibrate the
 spring tension( most airboxes develop a flat/worn spot on the circuit board
 from running at the same setting so this will prolong the life of the box)
to
 acquire a 2% co at idle, reset your idle speed with the screw in the
throttle
 housing, then fine tune the co to remain at 2% at idle w/ the airbox screw.
 Reconnect the idle stab. and you are done.I donot run w/ o2 sensor.I have
 found on all cars since the sensors came out in 76 on Volvos, that it makes
 the mixture too lean and too hot.OK the van spews out a tad more co% and HC,
 but no less than any car of the late 70s-80s, considering the fact that the
 o2 is supposed to keep the mixture at .07%, but it really just leans the
  hell out of the engine.This procedure is very effective on the digifant as
 well.The engine runs like the dickens.no flat spot, no hesitation, all go
 right to redline.I also run w/ a test pipe ala euro. I routinely run the van
 every year on a continuous ski trip of 1800 mi at about  200rpm shy of
 redline for 36 hrs straight.I think the vanagon engine is pretty amazing
 considering the fact that this 1.9 engine pushes my 4000lb box around at
 85mph+  all day.Unfortunately this procedure requires some way to read the
 exhaust gases, and, unless you have a machine, or access to one, you will be
 shooting in the dark.A dwell tach will not be accurate enough to read the
 subtle changes in co%. I also installed a custom 70C t/stat to keep engine
 temps in line( see posting to Todd) 
 Of course... I only use the vehicle off-road in order to comply w/ EPA
rules.
 
 Ed
  >>

The O2 sensor system uses a three way cat to control Hydrocarbons, Carbon
monoxide, and oxides of nitrogen.  The NOX is the real culprit in smog
formation and is the most damageing of the exhaust emissions.  This can only
be tested under load and is why the EPA tried to get states to go to
centralized emissions and dyno testing. Increasing the ignition timing also
increases the production of NOX as it increases the peak flame temparatures
of combustion. By setting the engines the way VW did, they were able to
eliminate a lot of emmission parts such as Air pumps(allows richer mixtures)
and EGR valves(that NOX thing).  By removing this stuff, you contribute to
alot more polution than you think and you justify the governments desire to
regulate your ability to work on your own car.  This is actualy tampering
with the Emission control systems and believe it or not is actually a Federal
offense(who's looking anyway).  I also have to ask how you pass emissions
testing with 2.0%CO.  In New York, anything 81 and later has to be at 1.2 %
or lower,(and idle at 100 rpm or lower).  As much as California is known for
strict emissions requirements, this limit seems very liberal.  If you
consider that your van should run at under .5%CO, your settings produce 4
times the pollution per mile than it should.  Although this is a 70's era
standard, newer cars should be cleaner and that difference is one reason we
are facing the clunker laws.  The government wants the old cars off the road.
 Believe it or not, 80% of automotive air pollution is caused by only 20% of
the cars on the road.  These cars are referred to as gross polluters.  The
gross polluters are the targets of emission control programs, junker programs
etc.  

Just my opinion and some facts,
Dennis H.