Hi all:

Took my '82 (Federal) to a Test Only station and failed fairly significantly
in the Hydrocarbons (HC) and Carbon Monoxide (CO).  I'd installed an O2
sensor in the crossover pipe but was getting very funky readings from the
sensor so after failing Smog I took the vehicle to a local VW dealer and had
them set the basic air/fuel mixture, which they did.  Went back to the Test
Only station and tried again.  This time the HC was OK but the CO was still
too high.

The engine is, I think, mechanically sound and the ignition components are
all in order with fairly new plugs, wires, distributor cap and rotor.  I've
also installed a Pertronix ignitor.  The catalytic converter is new.  Did
the oil change thing, brought the car in hot, etc.

Question 1: At this point, it seems like the mixture is still too rich and
the answer is to continue leaning it down.  Agree?

Question 2: Since the VW dealer isn't a Test Only station and can't test
emissions on a dyno like the Test Only stations do (I'm told the stress of
running on the dyno tends to push up the pollutants as compared to the
static idle and unloaded 2000 rpm tests) how the heck do you get adjustments
done without just going back, and going back, to the Test Only station?

Question 3: I've got my O2 sensor installed in the "J" bend of the crossover
pipe, shortly after the connection to the left-side heat exchanger.  Even
after VW set the basic mixture I'm still getting anomalous readings.
Sometimes when I hook up the voltmeter the reading will be "high" (like
.710) and slowly drift upward.  Sometimes the reading will be "low" (like
.387) and drift downward.  I've watched the voltage move up (and down)
across the .5 volts reading and it's very languid and constantly up or down
without the rapid up and down fluctuations I'm accustomed to seeing on my
California vehicle.  (I've used the O2 sensor in the California vehicle many
times to adjust the basic mixture.)  This is with 3 different O2 sensors, 2
of them new.  Does any of this suggest some fundamental problem that I've
overlooked?

TIA.
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Tom Young
Lafayette, CA 94549
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