[s-cars] ISV Cleaning, was: Translation

[Chad Clark]

At what temperature does this happen Marc?
Many years ago, mine used to do this while lukewarm until the engine was at 
normal operating temp. Coming to stop lights, somewhat coasting, the idle 
would drop to around 500rpm, bounce back up to around 1500 or so and then 
settle at 800. Sometimes the engine would kill requiring a restart. Cleaning 
the ISV **seemed** to help, but did not eliminate the problem. If I recall 
correctly, the fix was a new 02 sensor. Hasn't exhibited this problem since. 
HTH,

Chad


>From: Marc Gorelick <marc at frogville.net>
>To: S-cars mailing list <s-car-list at audifans.com>
>Subject: Re: [s-cars] ISV Cleaning, was: Translation
>Date: Thu, 16 Mar 2006 16:00:41 -0500
>
>Kent McLean wrote:
>
> >Toborg Michael (AC/ESC3-CC) * wrote:
> >
> >
> >>Multi Function Temp Switch
> >>Mass Air Flow (Sensor)
> >>Blow Off Valve
> >>Idle Stabilization Valve.
> >>
> >>Carb cleaner? Also curious about cleaning the ISV.
> >>
> >>
> >
> >http://www.audifans.com/twiki/bin/view/Audi/IsvCleaning
> >
>On a related note, perhaps someone can tell me if this is an ISV
>problem. Patient is a '93. Car idles great except for the problem below:
>
>When decelerating on approach to a red light, I usually just pop the car
>out of gear and hit the brakes. Often when I do this, the engine RPMs
>will coast down to the normal idle speed and then keep going, down to
>the vicinity of 500 RPMs or so. At this point, something realizes that
>the RPMs are too low and the engine speed rebounds well past the normal
>idle, up to as high as 2,000 RPMs.  After this the idle immediately
>returns to normal.
>
>This occurs about 1/3 of the time when I am decelerating as I approach a
>light. So far a bit of experimentation seems to suggest that if I stay
>off the brakes the problem doesn't occur.
>
>Since the idle is rock-steady other times, so I wonder if this is ISV
>related or something else entirely. My assumption is that an ISV problem
>would show itself at other times as well. Anyone seen a similar issue?
>
>Thanks for any feedback,
>
>Marc
>
>
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