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motronic help needed



ok, looking up the sensor at oxygensensors.com reveals that the car is probably
motronic.
i did some on-car checks and revealed the following:
- initial green-wire voltage: 0.0
- started engine, voltage steadily rose to 0.6 over a 30 second period.
- also noted that there was no idle fluctuation.
- re-connected wire, fluctuation began.
- connected meter to re-connected wire, revealed fluctuation from 0.2 to 0.8,
this fluctuation is in-sync with the idle speed fluctuation of 1000 to 1300 rpm.
this fluctuation occurs at ~5 second cycle.
- disconnected green wire, reading went to a steady 0.7 with the idle
fluctuation going away, settling at 1100 rpm.
so does this seem like a bad o2 sensor? its kinda throwing me, since its giving
what looks like a decent voltage.
Al


  ----- Original Message -----
  From: Brian Wagner
  To: Allyn ; Brian Wagner
  Sent: Tuesday, December 03, 2002 1:28 PM
  Subject: Re: motronic help needed


  No voltage, the car will continue to think it is cold and over compensate the
mixture. There is a procedure in the bentley to test this (I think) if not it is
in the haynes. Does it only do it after it is warm.

  Brian

   Allyn <amalventano@sc.rr.com> wrote:

    will it give me no voltage, or incorrect voltage?
    what would i see if its bad, in other words.
    thx
    Al

      ----- Original Message -----
      From: Brian Wagner
      To: Allyn ; brianm@earendel.org
      Cc: scirocco list
      Sent: Tuesday, December 03, 2002 1:07 PM
      Subject: Re: motronic help needed


      Check the 02 sensor if it is bad it can give you that effect.

       Allyn <amalventano@sc.rr.com> wrote:

        update:
        - from pete (thescirocco), this may actually be digifant 2.
        - cleaned out the ISV, did get some gunk out of it, but it wasnt enough
to stop
        it from working normally (verified by problem still existing).
        - did some more watching/listening/etc, and realized that its as if the
engine
        starts to idle rough anywhere below 1050 rpm. i'm sure the engine
management
        wants it to idle lower, but keeps bumping it back up to repeatedly
achieve a
        smooth idle, only to start over and head back to that hard-coded idle
speed.
        - i cranked down on the throttle body idle speed screw until i went
beyond the
        range of control of the isv and dropped the idle to 900. it idles a
little
        stuttery at that speed, but still holds a decent idle. i would leave it
like
        this, but that prevents the engine management from controling the idle,
which i
        would rather not do.
        - the cam! ! +exhaust may be causing the stumbly idle, or it may be
something else.
        i'm open to suggestions.
        - final note: this problem existed since i got the car. it has remained
constant
        as far as how bad it is.

        so... should i put a chip in this thing?
        thx in advance for help
        Al


        ----- Original Message -----
        From:
        To: "Allyn"
        Cc: "scirocco list"
        Sent: Monday, December 02, 2002 11:44 PM
        Subject: Re: motronic help needed


        >
        > Idle stab valve...
        > look up the audifans page for cleaning technique... basically clean
the
        > shot outta it w/ carb cleaner..
        >
        > On Mon, 2 Dec 2002, Allyn wrote:
        >
        > > car: 87 jetta wolfsburg 2 dr, 280 k miles
        > > mods: unknown cam, tt exhaust
        > > problem: idle fluctuates from 1000 to 1300 rpm at 5 second period.
smooth
        > > fluctuation, with no sudden changes i! n ! rpm.
        > > it seems as though if it went below 1000 it would start stumbling,
and the
        > > engine mgmt brings it back up to prevent a stall. it never gets a
chance to
        go
        > > that low, as it goes back up to 1300.
        > >
        > > suggestions?
        > >
        > > thx in advance
        > > Al
        > >
        > >
        > > _______________________________________________
        > > Scirocco-l mailing list
        > > Scirocco-l@scirocco.org
        > > http://neubayern.net/mailman/listinfo/scirocco-l
        > >
        >
        >


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