SQ problem ... solved

[ccohen5]

It was the temp sensor at the back of the head!  Many thanks to all for some
good advice.

The old one was functioning but the tech could not tell if it was working
within spec.  However some advice from Joern regarding its similarity to the
90/91 200, allowed me to extract some data from a Audi Training Manual for
this engine which had the Ohm/temp spec for this sensor.  AUDIJIM found the
sensor (a Baru equivalent of the Bosch OEM) item as well as the
multifunction/fan sensor jic.

The tech at Currys (VA) had tested the leakdown, fuel system and vacuum
which all cam out ok.  He found after replacing the sensor that he still had
to tweak the MAF.  now I do not know if he had played with this before he
isolated the problem to the temp sensor and had to correct it.  By way of
information, the first emission test run showed the idle at 250 ppm HC which
was over the 200 ppm limit.  Just a half turn clockwise on the MAF adj.
screw brought that down to the high 180s.  This was sufficient to pass the
idle and 2500 rpm tests.  The cat is still not hot enough, but I am hoping
that the next track visit will cure that.

Idle and smoothness throughout the rev range are detectably better.  Boost
may be a little down from its 1.7 BAR spec with the leaner mixture and
probably some Winter Gas.  So before I tweak it richer I am going to wait a
few months.

Colin