We may be on to something here, though ideally you would also want the
PC to log RPM's and perhaps throttle position. Do you have a source for
the voltage to serial converter?
According to the info I have, all O2 sensors put out the same signal,
regardless of the number of wires. The O2 sensor works like a battery
and puts out a variable voltage from 0 to 1.1 volts, with a "correct"
air fuel ratio being indicated by about .47 volts. Signal ground is the
case of the sensor on 1 wire units, but has a wire of its own on 2 wire
units, and Vsens+ is the signal wire. In those that have more than 1 or
2 wires, the others (particularly the ones that are the same color) are
to heat the sensor (they don't operate until they hit 600 degrees F). A
heated sensor gives reading on an engine whose exhaust gases haven't
heated the sensor to 600F yet.
So, most likely, on your 3 wire, the two wires that are the same color
are sensor heat, the third is the signal wire, and the signal ground is
the case.
Chris K.
Toby Atwater wrote:
>
> Does anybody know what output a 3 wire o2 sensor puts out? I had an idea
> awhile back, to weld on two adaptors on the outermost exhuast manifolds not
> only to check out overall mixture settings, but to balence the mixture
> settings on both carbs. screw in an oxy sensor on one, and a blank on the
> other.
>
> if the o2 sensor output is a simple voltage output depending on mix, I have
> a simple voltage -> digital converter that plugs right in a serial port on a
> laptop. Their software allows you to log the voltage over a period of time.
>
> Hook it up... go for a drive... Hook it up on the other, go for a drive,
> compare, adjust, and re-check.
>
> Thanks
>
> Toby
>
> |>
> |>Thanks for the team.net link.
> |>I don't know if I would prefer an analog gauge. Checking the
> |>fuel mixture
> |>under hard acceleration at high rpm requires checking the
> |>gauge out of the
> |>corner of your eye, colored LEDs might be easier for this.
> |>On my X1/9 I mounted the gauge "temporarily" right in front
> |>of me, up high
> |>until I have the dual carbs dialed in.
> |>
> |>I got my O2 sensor from Peter C. at a good price with
> |>instructions of how to
> |>hook it up.
> |>
> |>Ulix
> |>
> |>on 9/13/00 11:46 AM, Graziano, Michael at
> |>michael.graziano@csfb.com wrote:
> |>
> |>> FYI. I thought this was a great page, and very useful.
> |>I'm expecting my
> |>> Fuel/Air gauge this week. I bought a CB products analog
> |>gauge for about $50
> |>> along with a spark plug antifouler and an O2 sensor for an
> |>'87 Nissan 300ZX.
> |>> The sensor was about $50 from autozone (A three wire Bosch
> |>Unit). Well, I
> |>> actually have my old one from my 300ZX. I'll get the new
> |>one next month.
> |>>
> |>> Try http://www.cbperformance.com/catalog.asp?ProductID=598
> |>for the gauge.
> |>>
> |>> Glen, this might prove to be quite useful for setting up
> |>your Turbo Bugeye.
> |>>
> |>> Mike
> |>>
> |>>
> |>> -----Original Message-----
> |>> From: Nolan Penney [mailto:npenney@mde.state.md.us]
> |>> Sent: Friday, September 08, 2000 1:43 PM
> |>> To: Spitfires@autox.team.net
> |>> Subject: SU Needle selection and Air/Fuel Gauges
> |>>
> |>>
> |>>
> |>> http://www.team.net/www/morgan/tech/tuning.html
> |>>
> |>> This link is to an excellent web article on selecting SU
> |>needles using an
> |>> air/fuel gauge. This is why I think the gauge is so
> |>usefull. If you've
> |>> ever
> |>> considered trying to optimize the needle selection for your
> |>particular
> |>> engine,
> |>> this web page is vital reading. Not only for the knowledge
> |>you will gain,
> |>> but for the software in it.
> |>>
> |>> The SU Needle spreadsheet program is there for determining
> |>your needle
> |>> profile at each station, but for selecting other profiles.
> |>Good stuff! I
> |>> sucked
> |>> it into an Excell spreadsheet so I could have the pretty
> |>lines to admire in
> |>> a
> |>> graph. I'm a visual sort of guy, so I can grasp lines far
> |>quicker then I
> |>> can
> |>> grasp a column of numbers.
> |>>
> |>> Lastly, if this inspires you to want to install an air/fuel
> |>gauge, I suggest
> |>> you
> |>> at least look at this link.
> |>> http://www.autospeed.com/A_0020/P_7/article.html
> |>> It's about $65 now, which is roughly twice as much as a
> |>digital one costs,
> |>> but boy is this thing pretty, and right in keeping with a
> |>Spitfires analog
> |>> gauges.
> |>>
> |>>
> |>> This message is for the named person's use only. It may contain
> |>> confidential, proprietary or legally privileged information. No
> |>> confidentiality or privilege is waived or lost by any
> |>mistransmission.
> |>> If you receive this message in error, please immediately
> |>delete it and all
> |>> copies of it from your system, destroy any hard copies of
> |>it and notify the
> |>> sender. You must not, directly or indirectly, use,
> |>disclose, distribute,
> |>> print, or copy any part of this message if you are not the intended
> |>> recipient. CREDIT SUISSE GROUP and each of its subsidiaries
> |>each reserve
> |>> the right to monitor all e-mail communications through its
> |>networks. Any
> |>> views expressed in this message are those of the individual
> |>sender, except
> |>> where the message states otherwise and the sender is
> |>authorised to state
> |>> them to be the views of any such entity.
> |>> Unless otherwise stated, any pricing information given in
> |>this message is
> |>> indicative only, is subject to change and does not
> |>constitute an offer to
> |>> deal at any price quoted.
> |>> Any reference to the terms of executed transactions should
> |>be treated as
> |>> preliminary only and subject to our formal written confirmation.
> |>>
> |>>
> |>>
> |>>
> |>>
> |>
> |>--
> |> Ulix __/__,__
> |>___/__|\__
> |>..............................................(_o____o_)....<_
> O_____O_/...
> |>http://www.mirafiori.com/~ulix/ '67 Sprite '74 X1/9
> |>
> |>
> |>
|