Date:         Thu, 18 Jan 2001 11:58:07 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Help Educate Me
Comments: To: Dave Baker <djbaker@SPRYNET.COM>
In-Reply-To:  <002801c08169$d2dcaa80$3905313f@pavilion>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 11:15 AM 1/18/2001, Dave Baker wrote:
>Can anyone recommend a good book on the basics of VW engines?

Well, only the people with HTML capability are reading this at all (hint,
hint).  But many here would suggest you checkout a copy of _Bosch Fuel
Injection and Engine Management_, Robert Bentley Publishers, available from
Bus Depot, Bentley etc.

>   Bentley and Haynes assume you know (or don't need to know) how the
> catalytic converter works and what the O2 sensor does.

The cat takes in raw exhaust and passes it over a catalyst bed which
promotes oxidation and other chemical combinations to clean up stuff that's
either leftover from, (hydrocarbons),  or produced by (CO, oxides of
nitrogen) the combustion process.  The simplest cats only deal with mice I
mean hydrocarbons, and it's this ability to promote the burning of stuff
that's otherwise too thin to burn that makes them glow in the dark when
your mixture is way rich.

The O2 or lambda sensor is actually a tiny chemical battery which produces
a voltage if there is oxygen on one side of its active element and not the
other; and not if not.  It only works when it's hotter than about
300C/500F, so newer ones have a built in electric heater to get it started
faster.   It's too close to an on/off signal to be directly useful for
adjusting mixture, so the ECU biases it to half a volt and treats it as
"greater than half a volt means too rich, less than half a volt means too
lean, therefore whichever way it is correct until it goes the other way."


>  I'd like to get a better understanding of how all the various components
> discussed on this list work together to make the motor go.  You know,
> foot bone connected to the knee bone stuff.

Nonononono, the foot bone connects to the accelerator bone.  Sheesh!

david


David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"