Re: 5kcstq new to me.....temperature gauge, boost pressure?

[Wallace White <wallace@remdesign.com>]

Funny thing is, Nick, that my 5kcstq had most of the same problems when
I got it... plus a bunch that I found later!

> 1) the temperature gauge barely moves off of the peg on the cold side;

It is the large 4-wire sensor that you describe, the multi-function
temperature sensor, that produces the signal for the temp gauge. Replace
that and you should be set. The newer sensor actually has only 3 pins,
by the way. Apparently the 4th pin is power; the older sensors were
active, while the new ones are passive and supposedly more reliable.

I got my MFT sensor from Linda at Carlsen Audi for a good price; this
could be your first chance to order from her. Info is on the vendor page
of the list.

By the way, take a look at Scott Mockry's
http://www.teleport.com/~scottmo/ecusys.html#mfsense on this subject.

> 2) The back-up lights don't work, which is only a problem if I back over
> someone's bicycle when backing into the garage; haven't yet devoted my
> full attention to that one....

With your Bentley, you can trace the wiring diagram. They say that the
wires can get frayed at the trunk lid hinge, from all the bending, so
start by checking the circuit from the "kostal connector," which is a
big block of wires in the left-side footwell (Bentley shows it). That's
a convenient place to put power to the light circuit and see if they
come on, thus ruling out one half of the circuit or the other.

If your car really is like mine, the wiring downstream of the kostal
connector will prove to be fine. I haven't gotten around to the rest of
the debugging, but I have a hunch it's the backup switch itself. I found
its wires to be disconnected; too bad that connecting them didn't make
it work! Oh well, I'll check sometime.

> 3) Driver's side heated seat doesn't work (never had one in any other

That's one I haven't gotten around to, since I live in "sunny"
California. 

> 4) The computer on the dash says I'm getting 1.2 bars of boost max (.9
> bar ignition on, engine off; I'm at about 500 feet above sea level); it
> spools this up readily from maybe 3/4 throttle to WFO in the top 4
> gears, and the car pulls smoothly, but no kick in the pants like some
> other turbos I've driven.  My reading of professor Bentley implies that
> this is within spec, but it seems low to me.  I've checked all the

What's WFO? Anyway, go to Scott Mockry's pages at
http://www.teleport.com/~scottmo/ecusys.html#throt and read about the
throttle switch. At nearly WOT, one half of this switch should close,
telling the computer to activate the wastegate frequency valve, which
will affect the boost you see. This switch is well known to become
flakey with age. Chances are that a switch that even tests out okay with
a multimeter may not be working right all the time. Mine tested fine,
with resistance below 1 ohm when closed, but it wasn't (isn't, actually)
always working. 

How do you find that out? By hooking up a test light across the
wastegate solenoid, as Scott describes a little further down on the same
page.

> Other than the above, this is a great car.  All the running gear is
> tight; new steering rack, flawless body inside and out.

Glad you're enjoying your car, and welcome to the list!

- Wallace
  '87 5kcstq 151k