Pulsing gone! DEQ passed! Thanks!

[John Karasaki <johkar@teleport.com>]

Thanks to all those who responded to my questions regarding the pulsing
problems my TQC was experiencing.  Special thanks to Bryan Gunn whose
insights were particularly helpful.

You may recall my new to me '82 TQC had several problems.  It was very
difficult to start, ran mediocre until the oil temperature was at least 190
F,  pulsed or surged badly when operating under load between 3000 and 4000
RPM, failed to pass the emissions test at idle (at 2500 RPM it passed
easily), and the differential lock activation pull switch "wheezed" / whined
badly.

As mostly everything under the hood of this car is new or newer (head,
valves, turbo, all the tune-up stuff, sensors, etc.), I was concerned I had
a bad electrical gremlin on my hands.  This is what was wrong:

- Incorrect fuel pressures.  My mechanic "adjusted" the new control pressure
regulator and the "pulsing" went away.

- Poor main ground.  The screw that holds down about 4 or 5 brown wires on
the passenger side shock tower had stripped out the mounting hole.  This
caused an intermittent ground condition and the "surging" I was
experiencing.  Re-tapped the hole and added a nut under it;  that baby's not
coming loose again!  Surging stopped.

- No power to the heating elements in either the control pressure regulator
or the auxiliary air regulator.  This caused the hard start problem and poor
cold running problems I was experiencing.  My mechanic did not take the time
to troubleshoot the harness.  Instead he ran a new switched power lead to
each device.  Now the TQC starts right up like our 5kcst did (although not
as quickly as the V8 or 5ksw do).

- Valves too tightly adjusted.  The previous owner had a new head installed
in December of 1995.  His mechanic over tightened all the new valves.  I
suspect possibly thinking they would "loosen up" as they were broken in.
They didn't, so the emission levels were high (valve blow-by).  After the
valves were adjusted to factory tolerances it passed the emissions test with
flying colors.  This is with the Schrick cam BTW.

- Valve blow-by caused boost spikes greater than the differential lock
activation pull switch could handle.  The pressure line to this device comes
from a tee in the pressure line running to the boost gauge in the dash.  I
was experiencing over boost spikes before the valve adjustment, now they are
gone.  Boost comes on much earlier and I don't bury the boost needle unless
I have the boost manually adjusted up high.  The diff. lock switch is no
longer getting spiked, so the whining has stopped.

If anyone in the Portland, OR or Northwest area is having problems with
their turbo cars, I'd suggest you take your car to Al Blanchard at A&P
Specialties (503) 254-7310.  He knows these cars.  No guessing, no messing
around.  He walked systematically through all these repairs (I was mostly
watching and "suggesting") until everything was right.  He checked
everything, every system, every sensor.  His prices are very fair.  As there
were minimal parts involved, all the work I mentioned cost less than one
cheap v rated tire.

This of course is a major plug for Al and his shop.  He is one of the
reasons we decided to stay with Audis.  As long as we live on the West
Coast, he'll be the only one servicing our cars.  If you do decide to use
him, please mention me.  I'll get no discount or kick-back from this, but as
he does no advertising, I'm sure he'll appreciate the praises and word of
mouth referrals.  If you're the type that needs to grind someone on prices,
no matter how fair they may be, please refrain from doing it; Al's too good
of a guy to be put through that and I'd eventually get an ear full about it
latter.

Once again thanks to all.  :) :)
Regards,

John Karasaki

The Karasaki's, proud owners of AUDI automobiles

1981 Coupe
1982 TQC
1984 5000S Wagon
1990 V8