Date:         Fri, 05 May 1995 19:00:11 +0600
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         anon869@vt.edu (Christopher Bridge)
Subject:      Re: Aftermarket Electronic Ignition


>I'll give you all a hint, a $35 O2 sensor, the bung to be welded
>to the manifold and a digital voltmeter are all it really takes.
>There is a FAQ about this available from the fwd VW FAQ location
>(which I am not currently sure of the location).  I've personally
>been wondering how HALTECH and Berg can charge highway robbery
>prices for their little LED voltmeters.  In short it goes like
>this, the O2 sensor thread is same as 18mm sparkplug, you can
>get the bung from Parts Place or elsewhere or get a "spark plug
>no fouling" adapter from local parts store designed to keep
>plug OK in an oiling cylinder, the adapter is male thread one
>side, female on the other, grind off the male, drill a hole
>wherever (remember beyond the merger of the exhaust from each
>cylinder bank on a VW or before it if you want to tune each
>bank individually with 2 sensors) drill a hole and weld/braze
>her in.  Buy a generic heated (3 wire) sensor, around $30 even
>if you get a good deal, screw her in, appply 12V to heating leads
>look at the output with said meter, .45V is stoich, lower volts lean,
>higher means rich, two sensors are great for dual carbs.  Whole
>thing even if you buy a voltmeter should be less than $50.  Of course
>if you really must have a little LED display I can probably look
>in some old Radio electronics and find an article about building
>a little in line LED Voltmeter display for under $15.  BTW full
>instructions should be at lap.umd.edu in the vw_archives directory
>under ExhaustAnalyzer, ftp as anonymous login and you should be
>good, if anyone wants I will email you the full instructions if
>you don't have ftp capability.  Oh if you put 2 in close enough
>to the heads you probably don't even need the self heating style,
>you need it only if you are putting them far down line after the
>merger, check local speed shops for the bungs and plugs to replace
>the sensor if you don't want to leave it in, or if you only want
>to buy 1 sensor and tune 2 banks individually.  Thread is hypothetically
>18 x 0.5 mm but don't hold me to that.
>
>
>John Anderson (saving you money)
>ja@coe.wvu.edu
>'71 Westy, '90 Corrado G60

And how is it hooked up?  Do you just run a resistor in series with the 
sensor?  Or are you telling me this O2 sensor is actually generating 
voltage?  Iwould think that it is similar to other sensors which just vary 
the resistance with the change in what you're measuring.  So if a constant 
current is put through it, the varying resistance will produce the changing 
voltage?

P.S. been to the ftp site, but I am still lost.


  Chris Bridge
  
  ''71 Westy (Sportsmobile?)
  Favorite quotes:
  "Virginia Tech- yea, the best 5, or maybe even 6 years of your life."
  "They even throw in the stomach ulcers for free." 
  E-mail: cbridge@vt.edu