I had a different problem a few days ago, also in the Sierras.  Both occurred after an significant drop in elevation.  

The first occurred after spending a few days in Tuolumne Meadows and then driving from Tioga Pass (9900 ft.) down to Hwy. 395 (about 4000 ft.), and then again after spending a few days in the Devil's Postpile area, and then driving down from Minaret Summit (9100 ft), again to 395 (4000 ft.) for the trip home to So. Cal.  

Both times after completing the decent, and getting up to highway speeds for 5 - 10 minutes, the engine hesitated several times.  It felt something like running out of gas.  Then, after a few minutes it seemed to "cure" itself, as there were no further episodes between Bishop and Pasadena.

This may be related to the gas tank "THUNK" problem, which I still have, and the cure to which was so graciously provided by list-member Steven Ovemyer.

I was just curious if others had experienced something similar.

Fin Beven
Pasadena, CA
84 GL, Camper Conversion
90 Carat, Camper Conversion
  ----- Original Message ----- 
  From: Daniel E. Dedrick 
  To: vanagon@GERRY.VANAGON.COM 
  Sent: Wednesday, September 17, 2003 7:15 PM
  Subject: altitude woe

  Hello all -

  As I drove my 87 syncro over the Sierra Nevada last
  weekend, I noticed my usually peppy "boston bob" 2.1
  waterboxer getting quite sluggish at high altitudes.
  The westys were crusin' past me with no worries as I
  plugged along at ~20 mph in 2nd gear.

  This seemed to be most noticeable above 6000-7000 ft.
  When I returned to lower elevation, the engine regains
  health and runs like a champ.

  Any ideas what is causing this? Is there some sort of
  air pressure sensor?
  Thanks in advance!

  Cheers,
  Daniel

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