[s-cars] Boost leak - update, what am I missing here?

[Mike Claire]

Steve Mills suggested clogged cats.  I sure hope not - my Stromung cat-back
has less than 30K on it, and I keep the car running right.  I doubt I've
overheated or otherwise ruined them.



Mike

On 4/21/07, Steve Mills <s.b.mills at gmail.com> wrote:
>
> Mike-
>
>    Could also be clogged cats. When I bought it my 92 wouldn't make more
> than 1.4 BAR and even getting to that was paiiinnfulllllyyyyy
> ssssllloooowwwww. The PO chased what he thought was a boost leak and then a
> turbo problem for 6-8 months (new turbo, full Samcos, many $$$) and it was
> just clogged cats the whole time.
>
>   Cut off everything back of the turbo, install Stromung, whee haaaaa!  I
> can now peg it at 2.1 (on the factory gauge) at will.
>
>    HTH-
>
>    Steve
>
> On 4/21/07, Mike Claire <mike.claire at gmail.com> wrote:
>
> > A bunch of you guys replied to me last week with ideas, and I appreciate
> > the
> > help.  I've gone through everything suggested, and have read everything
> > about these issues I could find on Scott Mockrey's site,and STFA with
> > abandon.  I'm pretty much tapped - nothing to show for it.  I was
> > distracted
> > this week by new symptoms - and ultimately #3 coil just failed entirely.
> > Dead short.  That's fixed now and the car runs great again - except it's
> >
> > still low on boost.
> >
> > (subject is a '93 S4, MTM 1+ (Pastore) chip.  Used to indicate 22 lbs on
> > A-pillar gauge.  Now it peaks at 16 or 17, and backs down from there.)
> >
> > I'm either losing boost - or not making enough of it.  I don't know
> > where
> > else to look - what am I missing here?
> >
> > 1.  Pressure tested main intake plenum to 15 lbs with a compressor and
> > PVC
> > cleanout plugged into the intake boost.  Closed off Samco where it
> > enters
> > the intake, and the ISV - PASSED
> >
> > 2.  Pressure tested all the small hoses in the PCV circuit, water trap,
> > ECU
> > connection, boost gauge connection, etc. etc.  PASSED
> >
> > 3.  Removed BPV, plugged the Samco, plugged vacuum line (eliminate
> > possibility of BPV leaking pressure).   PASSED
> >
> > 4.  Removed silicone line from wastegate, plugged it shut (to test for
> > possibility of wastegate opening prematurely)  PASSED
> >
> > I can only think of two possibilities - either the turbo is no longer
> > capable of building normal boost, or the intake plenum is leaking at
> > pressures higher than 15 lbs.
> >
> > Could the turbo be failing?  It sounds the same and drives the same as
> > ever
> >
> >
> > I can take the Samco off the turbo outlet and pressure test from there,
> > but
> > I don't have compressor plug handy for that.
> >
> >
> > Before I do that - any ideas?
> >
> >
> > Mike
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>