[s-cars] Major league problem with S6 avant

[Robert Anderson]

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Hello fans,

I have a '95.5 S6 avant with 69,000 miles, Intended Acceleration Stage
III+ chip, big reds, eibach/Billsteins.  All was fine until about a week
ago. By fine, I mean the car screamed, staggering performance, very
happy with the chip.

So last week, I started spooling it up, and it was like it was hitting a
wall.  At about 5-10 psi, it felt like the pressure would cut out,
almost like a rev limiter, with some shuttering in the engine. I
replaced the bypass valve, checked the vacuum line, still the same
thing.

I then took it to Griffin Moterwerke in Berkeley.  They found that the
first two spark plugs near the fire wall had come loose, damaging the
threads and rubber connector boots around them.  They were able to
salvage the threads, thank God (or I'd be looking at a new head), they
replaced all the plugs, all the rubber connectors.  It seemed to be
working better, but still didn't seem to have the "umph" as originally.
I didn't really have a chance to put it to the test yesterday on the way
home.

But I did this morning with a rice burning Integra, normally fodder for
the S6.  Now it seems like the car spools up better to about 15 psi, but
it is still shuttering, like a vibration. I was racing this guy today,
threw it to 4th and slammed it.  I saw it go up to an indicate 20 psi,
but I felt a shuttering, just didn't have the normal pull, so I backed
off.  Shortly after, I smelled a burning smell, but that went away
shortly after.

Do you have any ideas?  I know it is difficult to diagnose by email, but
I thought you might at least be able to help me figure out possible
things to check.

Thanks in advance,

Robert Anderson

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