Date:         Mon, 21 Nov 94 14:04:35 EST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         dcarment@ccs.carleton.ca (David Carment)
Subject:      Re: Oxygen Sensor / Full Throttle Switch

Dave Kautz writes:
> 
> > David Carment writes;
> 
> > Finally when the vehicle was in for emmissons tests, was told by reputable
> > VW mechanic that the full throttle setup is marginal at best. He said you
> > could remove the device and would not notice the difference. I tend to
> > agree with him, at full throttle the difference is negligible; and yes the
> > switch is properly adjusted to the cam.
> > 
> > Conclusion - still unclear what the full throttle switch is intended to do
> > : advance the curve, richen the mixture or a combination; believe that is
> > not crucial but nevertheless a problem.
> > 
> > One solution - glancing through Bentley's at the bookstore; they have
> >  a detailed description of adjusting and testing the full throttle switch
> > and black box - this would be my next step....
> > 
> > Perhaps some one out there can throw some light on the issue (PhD's not
> > required).....DC
> > 
> 
> 
> 
>   I am always a little specualtive when mechanics start on the "those engineers
>   at the factory don't know what they're doing" - I doubt VW would have gone to
>   the expense of including the full throttle switch if it wasn't necessary. My
>   recollection of it's function (I'm at work and can't look it up) is that it
>   tells the computer to richen up the mixture at full throttle. This may not
>   result in more power but it may help keep peak temperatures and detonation
>   under control. I'd try and keep it working, if possible.
> 
> Einspritzerly yours,
> 
> Dave Kautz
> 
OK but can you tell us how to test it? The Hayne's is unclear and even
though i have replaced the "black box" it still seems to make little
noticeable difference. Your idea of peak temps is interesting though.
Earlier I had asked if removing the EGR would be detrimental, after all it
also reduces peak temps by inserting inert gas into the combustion chamber
no consensus on that one either ------DC
-- 

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David Carment
School of International Affairs
Carleton University
Ottawa, Ontario
K1S 5B6
voice - (613) 788-2600-6662
fax - (613) 788-2889
Email address: dcarment@ccs.carleton.ca
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