For what it's worth, I had similar problems steep climbing mountain roads in hot weather at 5000 foot elevation.� The road up to Big Bear Lake in Southern California, I'm sure you know it, pretty steep in sections, 90 degree F weather in August.� Engine suddenly reacted like it was starved, just choked, had to pull off the road (was in Vanagon Syndrome?; don't know, but added the capacitor to AFM just in case).� Anyway, I replaced the fuel filter on my 85 1.9 manual a couple years ago (replaced the fuel pump too since it was original and they were on sale at Bus Depot) and haven't had the problem since.� (Although I'm always waiting and watching for a recurrence.)� So maybe you're on the right track.

Rich
San Diego 

--- On Sat, 8/18/12, Rocket J Squirrel <camping.elliott@GMAIL.COM> wrote:

From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject: Start-Stop Syndrome Returns [addt'l-addt'l info]
To: vanagon@GERRY.VANAGON.COM
Date: Saturday, August 18, 2012, 9:33 AM

YET ANOTHER ADDITIONAL BIT 0' INFORMATION: This is tentative. Karl Wolz
asked whether the fuel pump had been buzzing when the engine was acting
wonky. I cannot say with any certainty whether I noticed that -- engine
noise and road noise, windows down -- but at some point on the trip I
did hear a not-loud but audible buzzing sound from behind.

I'm gonna check my fuel delivery rate and pressure.

--
Jack "Rocket j Squirrel" Elliott
1984 Westfalia, auto trans,
Bend, Ore.