Thanks G. Matthew for the primer on O2 sensor... will order it asap.

Any thoughts on the fresh air fan?

-- Dan Erlandson
Flemington, NJ
> danoer1@eclipse.net

> From: "G. Matthew Bulley" <gmbulley@BULLEY-HEWLETT.COM>
> Organization: Bulley-Hewlett
> Reply-To: "G. Matthew Bulley" <gmbulley@BULLEY-HEWLETT.COM>
> Date: Sat, 17 Aug 2002 09:55:22 -0400
> To: vanagon@GERRY.VANAGON.COM
> Subject: O2 Sensorama, was: A few unrelated questions
>
> O2 sensor not important, eh? Just for 'clean air wack-o's' eh?
>
>> From a functionality/engineering perspective, the O2 sensor is eyeballs
> of the fuel injection system. Without it, the ECU is practically blind.
>
> Think of it this way, your FI system has three basic components;
> sensors, injectors, and a brain to guide the quantity of fuel injected.
> In the category of "sensors" you have some that pick up semi-extraneous
> data on temperature around the motor, air flow coming in, etc. which it
> crunches into a firing solution for the injectors.
>
> The "final analysis" or QC for the fuel system is the O2 sensor. It sits
> in the exhaust stream and measures EXACTLY how the combustion process is
> working.
>
> The O2 sensor is the ONLY sensor in the FI system that actually measures
> how well the system is achieving its goal of delivering maximum HP and
> efficiency with each cylinder firing. The rest of the sensors are all
> "preliminary" data that proceeds the firing cycle. Does this make sense?
> The O2 sensor is like a QC guy at the end of a factory assembly line
> with a hotline to all of the production stations in the factory, and
> authority to tell each of those stations what to do to improve the
> product coming out of the factory.
>
> It is so vital to the operation of your engine, that VW put a warning
> light on the dash that reminds you to replace it every 30k. VW is not a
> warning-light-happy company. Failing to replace The 02 sensor eventually
> leads to the van reverting to the very lame "limp home" program in the
> EFI ECU. This limp home program has been known to ruin/melt catalytic
> converters because it tends to run very rich. It also fouls plugs, and
> yields poor mileage, and poor performance.
>
> So, if you haven't splurged for the amassively expensive ($30) O2
> sensor, stop being a cheapskate. Go get the sensor.
>
>
> Developing business and guiding change since 1996,
>
> G. Matthew Bulley
> Bulley-Hewlett
> Marketing & Communications
> Business: www.bulley-hewlett.com
> AIM = IExplain4u
> Phone: +1.919.658.1278
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf
> Of Dan Erlandson
> Sent: Saturday, August 17, 2002 9:18 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: A few unrelated questions
>
> Hey everyone,
>
> Just joined the list... great info.
>
> My 91 GL has 167 K on it with a rebuilt engine and rebuilt auto tranny.
> It
> is running fine these days, but a couple of questions
>
> 1.  I seem to read in the postings that the O2 sensor has some impact on
> the
> smoothness of the running of the engine.  I guess I thought it was just
> an
> emissions issue.  If it has never been replaced then I should replace
> it?
>
> 2.  The fresh air fan, a.k.a. defroster/heater  fan for the front seems
> to
> have gone bad.  Smoke and bad fumes when you turn it on.  No problem as
> long
> as it isn't on.  Bentley indicates that you have to pull the whole
> dashboard
> in order to access the fan.  I ordered one from VW and am close to
> starting
> the procedure.  Any advice?  Also picked up a couple of the shear bolts
> that
> hold the steering column to the dash (as per Bentley).
>
>
> -- Dan Erlandson
> Flemington, NJ
>> danoer1@eclipse.net
>