[s-cars] RE: S-CAR-List digest, Vol 1 #1944 - 12 msgs

[Cody Payne]

Hey Paul,
	Thank you for your reply...and thanks to others also.  So far I am "leaning" towards the Non-Bosch O2 Sensor that I put in my earlier this week.  I switched out the Borg-Warner O2 Sensor w/ a Audi OEM sensor and did not experience any of the cold running engine stalling problems.  The true test will be in the AM.
	As in my earlier post we have all but ruled-out ISV and Vacuum leak as both tests came back negative.  BPV has not been tested but is "audibly" working on each gear change w/ the Dahlback intake.

Stay Tuned

Thx Again

cp

-----Original Message-----
From: Paul Heneghan [mailto:paul at heneghan.co.uk]
Sent: Friday, October 24, 2003 8:52 PM
To: s-car-list at audifans.com
Cc: Cody Payne
Subject: RE: S-CAR-List digest, Vol 1 #1944 - 12 msgs


Hello Cody,

In this order, I would suspect the ISV, the Bypass Valve (the thing that
allows the output from the turbo to go back into the input when the throttle
is suddenly closed) and the throttle switch.

The ISVs on all my previous Audis have suffered from stickiness.  They open
and close (hence passing the output test), but they get so sticky that they
are unable to modulate quickly enough (hence the near dying of the engine
followed by the surge).  Try a bit more cleaning - use carb cleaner and make
sure it gets into the moving bits.

I usually try half-immersing the ISV in a jar of petrol, sealing the whole
thing with polythene, and then (at a safe distance from the petrol)
operating the ISV rapidly on and off with a 12V battery.  Obviously this
carries great risks from petrol vapour and the spark produced when
disconnecting the battery from the ISV.  However, the compensation is that
you get to see the black gunge being dissolved into the petrol

The safer way, but not as thorough, is just to spray the innards with carb
cleaner.

If you could borrow someone else's ISV, that would be well worthwhile.

Others know more about bypass valves than me.  Look in the archives for
discussions about Bosch, Bailey and Forge.

It is also possible that the throttle switch may be faulty.  I'm not sure
how it works with the AAN engine, but my previous I5 engines (KK, WC and KU)
all used the idle position of the throttle switch to tell the ISV when to
kick in.

Good luck.

Paul

> Message: 1
> Date: Fri, 24 Oct 2003 08:57:17 -0600
> From: "Cody Payne" <cpayne at bconnected.com>
> To: "'S-Car-List (E-mail)" <s-car-list at audifans.com>
> Subject: [s-cars] Cold Engine Stop-Light Stalling
>
> S-Car Gods,
> 	Gents...ok..the gremlins continue to haunt me on this stalling issue when
> the engine is cold. I have changed my O2 Sensor, Spark Plugs (Bosch
FDPOR),
> cleaned ISV and confirmed works w/ OutPut Tests.  But my car stalled again
> this AM coming to my 1st stoplight on the way to work about 1 min from
home
> It nearly stalled again at the 2nd stoplight which is another 1.5 min
> or so from the 1st but I was able to heal and toe her to keep it running.
> But once the car got warmed up on the highway it seemed to be ok.  Still
> seems I have a bit of sporadic idle when cold too...sort of bounces around
> 1.2K then settles down to 750-800.  Other then the stalling problem car is
> running very strong.  The only other thing I changed and have not changed
> back is my Stiffer WG spring?
>
> Vacuum leak? ISV bad? Fuel Pump? (It is only 1 year old) Fuel Filter?
(Only=
> 5K Old)
>
> Thx
>
> cp