I'm surprised nobody has mentioned getting Darrell Boehler's Digijet
tool.  I believe they're available now, right Darrell?

I have the Digifant tool and you can tell with a glance whether the
coil, starter, fuel pump, throttle switch, and hall sender are
working.  In addition, you can select voltage outputs from temp
1(inside AFM), temp 2, O2 sensor, battery voltage, and AFM.

The O2 sensor should be jumping up and down in voltage once it's
active (a few minutes after cold start).  If it's steady, it's
probably time to replace it.

The best part of the tool is that with the long ribbon cable, you can
get all of this from the driver's seat.  Furthermore, once you figure
out what the nominal values are for your van when it's running well,
you'll spot a problem in an instant.

-Karl

Karl F. Bloss - blosskf@apci.com or bloss@enter.net
'87 Vanagon GL Weekender "Beverley"; Trexlertown, PA
http://www.enter.net/~bloss/vw/
Busses by the Trail: http://www.enter.net/~bloss/vw/bbtt/