Recently every time I drove the bus (vanagon 84) in less than 5 miles 
the engine would cut out and restart.  Another 5 miles and again.
This is just an example but it always did it a couple of times before I
got to the next town.  

I found the auxiliary air intake elbow was cracked pretty high on the regulator side.

A trip to Napa for some suitable hose and a couple of clamps and I was off for another test.
It did it again.  Bummer.

The engine was surging at idle so I checked for more air leaks.  None visually found.

I adjusted the timing and off for another road test.  Power was still good.  No surging.
I went all the way to the next town and back without the cut outs.

Time will tell but this is the best signal I've gotten so far that the problem is fixed.
For those who search in the future here are the key words "Vanagon Syndrome, engine stalls".