[s-cars] Mystery Miss

[Robert Myers]

Hmmmm...  Swapping the PSO leads did move the miss.  I let the engine run 
just barely long enough to pull the injector connectors and then shut it 
off immediately while the miss was still present (before giving the engine 
enough time to warm up).  I restored the PSO wires to their original 
positions.  Fired it up again and the miss was gone.

<Thinking (a rare thing around here)>  I wonder if one of the crimp 
connections I did last week might be just a bit loose and not making 
perfect contact and by handling the harness I may have reestablished 
contact (for now).  No, that shouldn't be the problem because the miss 
would then have remained in the same place regardless of the PSO connection 
positions.  Perhaps this is a strange PSO failure but, if it is, it is not 
a failure mode I've seen before.  Usually, IME, when a PSO goes it is 
binary.  It either works or it doesn't.

Does anybody have a spare known good PSO they can loan for a brief test?

At 09:42 PM 9/29/2004 -0400, Bruce Mendel wrote:

>don't rule out the POS until you swap both connectors while it's cold and
>stumbling to see if the problem moves to a different cylinder...they have
>strange behavior, and change their behavior based on heat.
>----- Original Message -----
>From: "Robert Myers" <robert at s-cars.org>
>To: <s-car-list at audifans.com>
>Sent: Wednesday, September 29, 2004 9:34 PM
>Subject: [s-cars] Mystery Miss
>
>
> >
> > Hi Y'all,
> >
> > Thanks to all who responded about my son's dealings with his Mercyless
>Benz
> > stealer.  Apparently contacting the corporate offices helped.  He finally
> > has his car back from the stealer.  Now on to the topic of this post.
> >
> > My '95 urS6 (RS2ed) has developed a mystery miss.
> >
> > It happens only when the engine is stone cold.  It disappears after the
> > engine has run for less than two minutes and does not come back until the
> > next time the engine is stone cold.
> >
> > FWIW, I have localized the miss to cylinder #4.
> >
> > I have pretty much ruled out a fault with the PSO since the miss
>disappears
> > after the engine has warmed up a bit.
> >
> > I don't think it is a problem with a weak coil because there is absolutely
> > no miss at high boost which is when a weak coil would show up.
> >
> > I put new plugs in about a week ago so that shouldn't be the
> > problem.  Performance is superb after the engine warms up.
> >
> > Plug boots are reasonably fresh.
> >
> > The wires to/from the coils have been freshly reinsulated with shrink
> > wrap.  I am pretty confident that I did this job correctly.
> >
> > What in the name of the Audi gods remains?  Any ideas?
> >
> >
> > Bob
> > Random Bushism: "A tax cut is really one of the anecdotes to coming out of
> > an economic illness." George W. Bush, on The Edge With Paula Zahn, Sept.
> > 18, 2000
> > _____
> > Robert Myers   304-574-2372
> > Fayetteville, WV
> > '95 urS6  Cashmere Grey
> > _____
> >
>
>
>----------------------------------------------------------------------------
>----
>
>
> > _______________________________________________
> > S-CAR-List mailing list
> > S-CAR-List at audifans.com
> > http://www.audifans.com/mailman/listinfo/s-car-list
> >

Bob
Random Bushism: "If the East Timorians decide to revolt, I'm sure I'll have 
a statement." George W Bush, Quoted by Maureen Dowd in the New York Times, 
June 16, 1999
_____
Robert Myers  304-574-2372
Fayetteville, WV
urS6 - Cashmere Grey
_____