MAC05A - KG engine

[quk@isham-research.demon.co.uk (Phil Payne)]

Does anyone know anything about this beast?

I was faced with one on Saturday, with the owner complaining about high
idle (3500rpm - shagged ISV) and high fuel consumption (bad setup).
The ECU boost line was also a little porous - frantic pumping with the
MityVac required to show any pointer deflection!

Replacing the boost line, ISV and setting up CO/idle screw correctly
cured his immediate problems, but I have a few questions regarding the
MAC05A and the KG engine:

a) There's a 'check engine' light but it would appear the ECU doesn't
   store codes in the accepted way.  The fuel pump relay has no fuse
   holder. Replacing it with one that does proves that the wiring for
   it is present, because the 'check engine' light then illuminates
   when a fuse is inserted.  But - no codes.

b) There's a short length of fabric-covered 3.5mm hose attached to the
   wastegate upper chamber - but it doesn't go anywhere.  Should it?

The KG is the first engine fitted to the 200TQ (this was an Avant) in
the UK - 1987 model year.  It uses CIS-E with the system pressure
regulator integral to the metering head and the control pressure
regulator controlled by a switchover/frequency valve driven (I assume)
by the ECU.  It has the two part idle/WOT switch (with the WOT component
dead on this particular car - owner is to replace).  It also has the
smaller two-pass intercooler.

In passing - a nice car.  Full black leather, reasonable black bodywork,
237k miles and no rattles!  Probably good for another 100k at least.

--
 Phil Payne
 UK Audi quattro Owners Club