The lack of power with open throttle coming back as throttle is lifted
indicates fuel starvation. Clogged tank screens or pump inlet filter. You
need to test the fuel pressure under load. Bad O2 sensor would be always
bad with improvement at full throttle or with quick ignition key blip for
reset.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Brendan Slevin
Sent: Wednesday, December 26, 2007 1:15 PM
To: vanagon@GERRY.VANAGON.COM
Subject: 1.9 low power problem

Well, Totoro has been running great since the rebuild but now (last three
days) has developed a hesitation.  It drives fine in town but when I try
to
get on it to get up to highway speed in 3rd or 4th it bogs way down and if
I
don't lift seems as though it would die all they way.  If I lift my foot
and
slow a bit and down shift it seems fine again until the instant I try to
speed up again.  Happening right around 4000 rpm on the tach.  Plugged cat
maybe?  I took some connections apart and cleaned them with elec. Cleaner
in
a spray can.  Even unplugged the ecu and plugged it back in.  I did this
all
this morning before starting the van.  When I started it and warmed it up
I
took it for a test drive.  Was fine for about three miles and then started
it again.  We've had a ton of snow and slush last week so I think
something
got wet.  Maybe the water causing the problem was frozen this morning (25
degrees F)  and didn't cause a problem until thawing out.  Also, am I
supposed to have and splash guards around the engine?  Seems to be hole to
mount some on both side in the wheel wells.

Brendan
I have measured out my life with coffee spoons. -T.S. Eliot