[s-cars] Funky Cruise Control FIXED

[The Gagnons]

Hey Everybody,

I posted  a question about a mis-behaving cruise control a few months back.
I finally got around to investigating it a week or so ago.  It turned out to
be a clogged vent at the vacuum pump.  Paul Gailus was pretty much right
about the problem except the solenoid was fine and it was just crud
build-up. The pump is located in the left fender behind the power steering
reservoir and coolant reservoir.

Thanks Paul!

Jack

-----Original Message-----
From: Paul Gailus [mailto:gailus at mindspring.com]
Sent: Monday, August 18, 2003 11:02 PM
To: The Gagnons
Subject: Re: [s-cars] Cruise control


Jack,

It sounds like the solenoid controlled vent valve in the vacuum pump
might be sticking so that it doesn't always open when the cruise
control module activates it (by grounding a pin to this solenoid).
In other words, the vacuum pump can turn on to apply more throttle
via the actuator diaphragm, but the solenoid valve can't vent to the
atmosphere to release the diaphragm and back off the throttle.
The brake or clutch vent valves would still be able to vent off the
vaccuum independently of the solenoid vent valve in order to
shut off the actuator.

It's also possible that there's a bad connection to this solenoid valve
either on the connector going to the vaccum pump or the one going
to the control unit. So you might try pullling these connectors on and off.
If you've got a Bentley, there's some info on page W27-24 and on the
electrical page X81.

Paul

----- Original Message -----
From: The Gagnons <bullitt at gwi.net>
To: S-Car-List <s-car-list at audifans.com>
Sent: Sunday, August 17, 2003 10:06 PM
Subject: [s-cars] Cruise control


> Hello,
>
> The cruise control on my 92 S4 has started to act strangely.  After
setting
> the speed the car will cruise for a short while and then will start to
gain
> speed and continue to accelerate until I finally have to hit the brake or
> clutch pedal to cancel the cruise control.  It seems like it will gain
speed
> after it applies more throttle to climb a hill.  Another symptom is that
the
> cancel feature on the stalk does not work any longer.
>
>  I have had cruise controls in Audi's malfunction in the past, but never
> like this.  The usual problem is that the cruise will not engage at all
due
> to leaky vacuum vent valve switches.  Anyone know what  is going on here?
>
> Thank
>
> Jack
>
>
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