If considering 70 an accomplishment on flat ground at sea level I suspect
you do have an overall performance problem.  I always start with the basics
beginning with engine compression and a leak down test and eventually ending
up at fuel delivery and exhaust restrictions. A partially clogged fuel tank
outlet or restricted filter before the pump will raise havoc at altitude as
the fuel vaporizes at the pump inlet. All things need to be tested and
proper operation confirmed. A failed catalyst can clog the muffler with the
pieces and cause all sorts of performance problems. You need to do some
digging.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
KevinPGilleran
Sent: Tuesday, January 21, 2014 10:25 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: 1991 westy - altitude sickness?

Dennis,
When we were at altitude I had the gas pedal to the floor of the vehicle, on
a straightaway not incline, so I think that there was and is a mechanical
issue. Once we dropped back down to essentially 0 altitude then the van was
working fine so there is some hose loose or sensor that appears to not be
functioning properly.

Sincerely,

Kevin P. Gilleran

-----Original Message-----
From: Dennis Haynes [mailto:d23haynes57@hotmail.com]
Sent: Tuesday, January 21, 2014 3:36 AM
To: 'KevinPGilleran'; vanagon@GERRY.VANAGON.COM
Subject: RE: 1991 westy - altitude sickness?

From an engineering point of view a naturally aspirated engine loses 3% for
each 1,000 ft. elevation. The O2 sensor should have no problem compensating
for 5,000 ft. to keep the mixture close. Where you able to get over 50 if
you down-shifted? Manual or automatic? If automatic is the kick down working
properly. Inability to take hills in an automatic can also be a sign of a
bad torque converter.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
KevinPGilleran
Sent: Monday, January 20, 2014 4:07 PM
To: vanagon@GERRY.VANAGON.COM
Subject: 1991 westy - altitude sickness?

All,

On my last trip out to the Grand Canyon and then circling clockwise around
to Zion I found that my 1991 westy had problems with what I can only imagine
is the altitude (4970 ft at Kanab Utah). I could barely get the van up to 50
miles per hour the entire time we were at elevation. But once we dropped
back down into California and were back on highway 5 (400 feet or so) we
were back up 70 mph no problem.

Any ideas of where I should start on this issue would be much appreciated.

Sincerely,

Kevin P. Gilleran