Re: C-GT tune up

[Huw Powell <human@nh.ultranet.com>]

> Apart from the new cap/rotor/plugs/wires and stuff, what kind of
> adjustments can I make myself.  I remember having a guy tune up my old '85
> C-GT, and he had an exhaust gas analyzer or something, and he adjusted the
> fuel mixture at the fuel distributor.  I don't have one of these
> analyzers, are they absolutely necessary?

This is your excuse to buy a nice yellow meter and shiny chrome timing
light at Sears...

Get a meter with a duty cycle setting (or dwell, and do the math, 50% =
45 degrees on 4 cyl) and measure the frequency valve duty cycle at the
unattached two wire connector floating around by your intake boot.  At
idle it's supposed to be around 50%.  (this is the crude way of doing
what your mech. did above)

Measure the OXS output voltage, should swing around 700 mV over a few
second cycle.  This is the green (?) wire with a black bootie connected
to a tan plastic plug, same general area.  Test it connected -
unconnected it won't let the computer adjust the mixture to keep the
voltage right.

Check your timing.  Stock is 6 deg. BTDC, you can advance it for more
power, up to 16-20 degrees, just find a steep hill and check for knock
before deciding you're done.

Check and clean any electrical connections you can get to under the
hood.  Check the ground tabs under the dash on the left for corrosion
etc.  Silicone dielectric grease is a nice way to ensure future
conductivity.

Give your vacuum hoses a careful look.  The lines are cheap to replace,
the rubber bits aren't too bad, available at dealers, usually special
order.

Air filter, oil change & filter.

Wash the windshield inside and out.  (this really helps...)

I'm sure I'm forgetting something obvious, but that's what these cars
are all about.

What a great way to spend a Saturday afternoon!
-- 
Huw Powell

http://www.thebook.com/human-speakers/audi-main.htm