The throttle bodies DO close all the way.  The idle adjustment screw allows
some air to get by, and on the 1.9l TBs, there is a hole in the plate to
allow some additional bypass.  The wear on the inside of the throat is
caused by bad bushings, which allow the butterfly to seat in a different
location each time you take your foot off the accelerator.

Karl Wolz

----- Original Message -----
From: "Kenneth D Lewis" <kdlewis@juno.com>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, May 19, 2001 10:31 AM
Subject: Re: rebuilding throttle body

> Mark;
>         I see what you are saying, I just do not understand why. The
> butterfly are almost identical are they not? The throttle body's should
> never close all the way anyway,if the idle stop is set correctly. Why
> would it wear grooves in the side?
>
>
>
> Good Luck and Drive Safely
> Ken Lewis
> 86 Crewcab,60 356
> http://Neksiwel.20m.com/
>
>
> On Fri, 18 May 2001 14:51:33 "Mark McCulley" <transporter99@hotmail.com>
> writes:
> > Ken and Mark,
> >
> > The problem with the throttle body is quite different from the
> > problem with
> > worn bushings on a carburator. What typically happens with a
> > carburator is
> > the bushings on the butterfly plate shaft wear out resulting in an
> > air leak
> > and a too-lean mixture. This is easily fixed by rebushing the shaft.
> > What
> > happens on the 2.1l throttle body is the throttle plate wears
> > grooves into
> > the inside of the throttle body......................
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