My first Vanagon list message... (am I supposed to feel nervous?  'cause I
do, for some reason.)  Well, hello everyone, I've been reading up on the
archive to see if I could find an experience identical to mine, but
decided to post a message anyway.  If anyone knows of a helpful thread I
can refer to, or has had a similar problem, please help me! I treat my van
so nice, why does she do this to me...  Here's the rub:

Dela, our '84 Westy, has a problem with highway driving.  We drove all the
way from Ontario to Alberta and back last summer without a single
occurence of this problem but it has come on fast and furious in the past
three months.  After about an hour of driving, at about 85-90 km/h (I'm a
gas miser, what can I say) the engine will begin to misfire, the bucking
increasing in pitch and fervour the farther I go.  I wish I had a tach,
but I estimate that the problem occurs mostly at about 2500-3000 rpm.  One
band-aid solution, which makes me think it may be a fuel-delivery problem,
is gas-line antifreeze or 'injector treatment'.  Crude, but gets the
family home.  The problem happens in dry weather and wet.  I use only
92-octane fuel.  I've replaced O2 sensor, cap&rotor, ig.wires, fuel
filter, lots of stuff but the problem WON'T GO AWAY.

Do you sense my frustration?  Help!
Thanks in advance...

Marcus Elia