Date: Fri, 9 Sep 2005 12:05:34 -0700
Reply-To: Doug in Calif <vanagon@ASTOUND.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Doug in Calif <vanagon@ASTOUND.NET>
Subject: Re: NOx high
Content-Type: text/plain; charset="iso-8859-1"
Jim, not to disagree with you, but your comment leaves me wondering why my
mechanic who has had a local shop here in the bay area for over 30 years and
he has been doing and still does smog for somewhat exclusively German cars,
told me specifically that you want to get it checked on a cold morning vs.
hot afternoon to get the NOx as low as possible. Could it be a minimal but
perhaps readable effect?
Doug
----- Original Message -----
From: "jimt" <camper@tactical-bus.info>
To: "Doug in Calif" <vanagon@astound.net>; <vanagon@GERRY.VANAGON.COM>
Sent: Friday, September 09, 2005 8:05 AM
Subject: Re: NOx high
> Induction air will have little to no effect on the combustion chamber as
> concerning the burn temperatures for nox creation. Depending on year of
the
> vanagon (AC vs WB) there is an EGR but it is usually nonfunctional from
> holes in the system from corrosion.
>
> Too lean will increase some nox and off timing will really increase nox.
> For fun find a shop with the old style emissions testing equip and hook
up.
> Rotate the dizzie just a little bit one way and then the other and watch
> what happens to your readings for nox and hc. When timing is right both
will
> be at a good pass reading (your mixture may have to be adjusted a tweak if
> you donšt have an O2 system) if your everything else is in good repair.
> Ie filters, cat, wires, plugs, oil. All the little things that should be
> checked or changed before testing.
> jimt
> On 9/9/05 7:53 AM, "Doug in Calif" <vanagon@ASTOUND.NET> wrote:
>
> > Dennis,
> > Its my understanding after discussing with my mechanic that the outside
air
> > temp may make a large difference on the NOx when you take your vanagon
in
> > for smog check.
> > A 100 degree day vs. say a 30 degree day.
> >
> > Doug
> >
> >
> > ----- Original Message -----
> > From: "Dennis Haynes" <dhaynes@OPTONLINE.NET>
> > To: <vanagon@GERRY.VANAGON.COM>
> > Sent: Friday, September 09, 2005 5:50 AM
> > Subject: Re: NOx high
> >
> >
> >> NOx is caused by excessively high combustion temperatures. Usual causes
> >> are a lean fuel mixture or over advanced ignition timing. Since the
> >> Vanagon does not use EGR, the engine settings are extremely critical.
> >> The Cat has the major job of reducing the NOx and all aftermarket cats
> >> do not have as much active material as the original so they do not last
> >> that long.
> >>
> >> Dennis
> >>
> >> -----Original Message-----
> >> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> >> Of Mike Miller
> >> Sent: Friday, September 09, 2005 12:09 AM
> >> To: vanagon@GERRY.VANAGON.COM
> >> Subject: NOx high
> >>
> >> Vanners,
> >>
> >> My van passed smog but the NOx was just below the maximum. New cat two
> >> years
> >> ago.
> >>
> >> Any likely causes to look at?
> >>
> >> TIA
> >>
> >> Mike
> >
> >
>
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