Thanks David,
I've just got to find the system to narrow the possibilities to fewer
"suspects" during this diagnostic period!  Before leaving for Mexico
last winter, I did attempt a cure by the following:

    1.  Had a new Bosch fuel filter installed.
    2.  Was told the fuel pump "appeared to working fine."
    3.  Because it was cheap, my mechanic replaced some very inexpensive
fuel relay sensor, or somesuch.  No help.
    4.  The AFM was replaced with a new one---& tho my loss of power/cutting
out prob started with this incorrectly adjusted new AFM,  I did not
experience any further power loss/cuttingout
problems for 5 months.  Go figure.

Other than this, she's got great getup 'n go!  Normally, I get just under 20
mpg on the highway, tho I seldom drive over 55.  She'll do much more, but
I've learned to enjoy an easy, rubbernecking, cruise.  If it
weren't for the inherent danger of driving in Mexico,  I would just accept
this power loss as a quirk & let it go at that.  But I could be
rear ended & killed by a Big Rig, and that's no lie.
    I've got a few months to figure it out.  FYI--one Vanagon owner
explained the fuel harness fix like this:  there is a plastic part in the
AFM, which, over time, is rubbed by a metal part which causes the
buildup of static electricity.
     Won't you be on the road soon with your dog & pony show?
Ciao,
Phaedra