The 8 second surge doesn't ring any bells, but check the following:

Try first seeing if the throttle-closed switch is closing when the throttle
is closed (and opening when opened...).

Also check Oxy sensor - if this is gone, your mileage will suffer lots.

Remember also that the Vanagon distributor likes to burn out the rotor,
especially if it isn't a genuine Bosch (check the resistance if it doesn't
look burned).   This can cause severe power loss and mileage drop.

Next (or maybe first...) I would also check to see if any of the rubber
hoses in the air inlet side are cracked or loose (maybe they flex and leak
when the engine is under load and torqued to one side?

Finally, I would consider the (expensive) Air Flow Meter harness upgrade if
you haven't done it, or possibly the much less expensive capacitor
retrofit, or AFM wiper track cleaning.   (These are documented in the
archives if you can get to them.)
The general symptom of the AFM problem is a momentary cutting out of the
engine, rather than surging, but I suppose this might feel like surging
sometimes.

Let us know what you find (or don't).

Dave
87 Wolfsburg
90 Westfalia (both with AFM fix, new rotors, new Oxy sensors...)

At 04:21 AM 2/18/99 -0800, MtnGal wrote:
>On the way back up to the mountains (heading home after school), I noticed
>on the grade that the motor revved/surged at timed 8 second intervals (?)
>any ideas where to begin trouble shooting?
>At fill up I averaged 11 mpg.  bummed.
>
>MtnGal@Sierratel.com (Debi)
>Bronze 84 VW-Vanagon GL  (83.5)
>ICQ: 11427418 /Friend
>