Hi T-Man,
        You have mentioned many of the potential trouble spots for stalling in
your post. My list of intermittent vanagon stalling incidents is the following:
1. Partially broken big red wire on the back of the alternator, couldn't be
seen until I took it off the alternator and saw the broken strands of
copper in the ring connector. Recrimped wire in new connector, problem solved.
2. Bad throttle position switch, caused stalling at startup. Test revealed
bad contact in it, replaced it.
3. Bad Hall sensor/distributor. Van gave hints that I didn't recognize
before it completely failed. Occasional ignition miss ( that I foolishly
pretended weren't happening) while driving evolved into intermittent
stalling and finally no start. I checked all the components in the ignition
system gave it a tuneup with no success. Finally took out distributor and
the shaft had way too much play down where it connects to the drive shaft
at the cam. This should be tight, not much wiggle. Replaced distributor
problem solved. Maybe excess play destroyed Hall sensor or prevented it
from functioning.
4. Bad ECU's had an extra that fixed the problem, then that went bad too.
They were old ECU's. I have another van so could check this easily. Was
told by mechanic that old coils can fry ECU's, don't know if true but I
replaced the coil too and it stopped eating ECU's.
5. Bad temp II sensors ( twice ) the blue ones, although this wasn't
intermittent and is obvious when it happens, van started and ran until warm
and then would run too rich, with black smoke and gas fumes coming out of
the exhaust.
6. Bad splice connection at O2 sensor wires, rain would infiltrate bad
solder connection causing stalling and low power.
7. Broken power steering switch wires, I forgot about checking this
connection and spent useless hours checking all of the above.
Hope this helps.
Rick Koller
'90 syncro westie
'91 gl, '91 carat