So I replaced the distributor cap, rotor, plugs & wires, and now my
85 westy no longer seems sensitive to water.   But it still runs
rough at idle, misfires a bit and smells gassy.  If you rev it up at
all it smooths out, and seems to drive just fine on the street and
freeway.

I tried disconnecting the idle stabilizer (connecting the two
connectors together).  The result was that the van would still start,
but it seemed to want to idle at around 500 rpm (and would therefore
frequently die).  This was with warm oil on a 70 degree day.

Question:  How should a properly tuned vanagon behave when you remove
the idle stabilizer from the circuit?  I'm wondering if maybe it's
mis-tuned a bit, and the idle stabilizer is trying it's best to
correct, but it can't fully cover up the problem and results in the
misfiring?