i agree with brent, it's probably leaning out.  i changed to k&n on three
other vehicles that i have owned, and have had similar problems before. (not
vanagon) most obvious was when i change from paper to k&n on a set up with
dual sidedraft mikunis on a samurai.  had to re jet the carbs...

mike

 > Date:    Tue, 16 Apr 2002 17:20:32 -0700
> From:    Brent Christensen <sbsyncro@HOTMAIL.COM>
> Subject: Re: K&N Filter and.....
>
> Sounds to me like it may be leaning out at the low end.  With that new
> filter, you are able to suck in a lot more air (in theory).  The AFM may
be
> sending the right signal, but the ECU may not be programmed for the
correct
> fuel mixture curve, since it is based on the flow characteristics of the K
&
> N filter.  This is assuming that the filter does indeed flow *that* much
> more air...
>
> The "performaance chip" is supposed to correct this problem.  I have a K &
N
> on the way, and will test it with and without my performance chip-based
ECU
> and see if it behaves the way that you describe.
>
> Nice to hear that the difference was that noticeable.  Was your other
filter
> particularly dirty?  (Can you see light through it?)
>
> Brent Christensen
> '89 Syncro Westy
> Santa Barbara, CA
>
> ----- Original Message -----
> From: "Jeremy Speer" <jspeer@POBOX.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Tuesday, April 16, 2002 4:38 PM
> Subject: K&N Filter and.....
>
>
> > All,
> >
> > I just installed a K&N filter on my '89 Westy. Huzzah!
> >
> > From a modest local test drive i can honestly say that third gear pickup
> > seems noticeably better. Really, no joke, i press the gas and she just
> > leaps! Also throttle response in general seems slightly better.
> >
> > However, once warm, i seem to have a big dead area in the low RPM range
of
> > 2nd, 3rd and 4th gears that i want to believe is due to an aging air
flow
> > meter.
> >
> > The symptom is, once the engine is warm, when i shift from 1st to 2nd,
> > unless i rev it way up, the pickup just dies when i shift to 2nd.
However,
> > if i keep my foot on the gas *in the exact same position*, the RPMs
slowly
> > build and then suddenly the vehicle just shoots ahead, i shift to 3rd
and
> > the cycle repeats. If i wind it up to 3900-4000 RPMs before shifting the
> > "dead zone" is largely avoided.
> >
> > This does not happen when the engine is cold, i.e. i can shift from 1st
to
> > 2nd at 3000 rpms and she will just dig herself out of the RPM hole
> smoothly
> > and predictably. I'm noticing this now because, if you've been watching
> the
> > news, Minnesota broke all records yesterday by hitting 92F! We tied with
> > Phoenix, AZ! Hence my engine is warm MUCH faster than two weeks ago when
> we
> > had 8 inches of snow.
> >
> > So... air flow meter, right? right?
> >
> > -jspeer
> >
> > '89 Westy, "Mystery Machine"