For all those recommending to Carl the capacitor fix and wire harness,
he stated in his initial post that he already bought the harness from
the dealer and it made no difference.

Carl - the capacitor fix you've been told about is the $1.50 version of
that $160 thing the dealer gave you.  (hey, I've got one of them too,
although I found mine for $119)

Given your choices so far:
> 1.  Ignition switch  ($30 to replace)
> 2.  Air sensor  ($450 for part)
> 3.  fuel filter
> 4.  Fuel pump
> 5.  Water in cooling system
> 6.  some pretty technical solution that involves splicing a resistor > (or something like that...I'm pretty thick when it comes to > electricity) into pin number 4 on the air  intake harness
> 7  and a few more that ZI can't think of just this moment.  I left the
> printed messages at work.

1 - well, I'm at least one of the people that suggested that one (the
heavy keychain culprit)

2 you can definately get for cheaper (someone already referred you) but
I'm not sure if it'd completely cut you off if bad, but I guess it could

3 and 4 possible but questionable given that resetting system fixes
things temporarily

5 no; although water in fuel system could

6 you've already done.

8 (recently suggested) was temp sensor - no; at least when mine went out
it produced a chug-chug-cough-sputter routine, never just cut out on me

Another to add to your list, vacuum leak although this too is very
questionable - I had one of the lines that plug into the boot by the air
box come completely off and it killed instantly, would not could not
start.  An intermittent leak of significant proportions (perhaps a hose
where the bottom has rubbed thin and if its jiggled just right springs
its leak) could do this.

Carl, make sure I'm repeating you properly, but the problem is it
completely shuts off like you've turned off the ignition key, right?  No
cough-cough, no hesitation, no loss of power, no recovery other than
re-starting the ignition - right??

hope to help,
Tonya
87 Vanagon GL Wolfs