Date:         Sun, 12 Sep 2004 22:44:52 -0400
Reply-To:     Jonathan Farrugia <jfarrugi@UMICH.EDU>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Jonathan Farrugia <jfarrugi@UMICH.EDU>
Subject:      Re: CIS-E fuel injection help needed
Comments: To: Eric Zeno <vw4x4@FYI.NET>
In-Reply-To:  <Pine.GSO.4.21.0409121853440.5670-100000@oola>
Content-Type: TEXT/PLAIN; charset=US-ASCII

Eric

the oxygen sensor shouldn't have a steady reading at any time.  it should
be doing what is called cross counting, that is swinging from 0-1 volt at
all times.  the more crosses across the .45 volt mark the better.  .45
volts is the voltage that the oxygen sensor would put out if your burn
mixture was constantly perfect.  since the burn mixture is never perfect
it will swing across that voltage of .45 as the fuel injection system
continually tries to correct the burn mixture to perfect.

with those readings i would guess that you have a bad oxygen sensor.  as a
side note the whole system needs to be up to temperature before you do
your testing.  i would suggest that the coolant needle be half way on the
gage before you do your testing.  this is because the exhaust gas needs to
heat the oxygen sensor up for it to work properly.

jonathan

On Sun, 12 Sep 2004, Eric Zeno wrote:

> Hi all,
>    I have a inline 4 cly. VW enigne in one of my syncros with
> cis-e fuel system.  Problem: ran great for first 5 thousand miles.
> During a long trip it started missing, with a rough idle.  The
> fuel system is out of a 1988 Vw fox.  I've replaced a ton of parts
> and nothing has helped.  The o2 sensor reads less than .1 Volt
> at idle. Reving the motors it climbs to .65 Volts and then
> down at higher RPM's to around .4 Volts.  The spark plugs
> show a lean burn condition.  Any guesses.  Anyone have this system
> in anything else, care to comment?
>
>
>
>             Eric                   86-VW4x4
>             vw4x4@fyi.net          86-SS Syncro
>             Pittsburgh, PA USA     1936-Chrysler
>                                    92-Jetta GWC
>             www.fyi.net/~vw4x4/vw4x4.htm
>
>
>