Re: Aux Air Regulator

[ti@bazooka.amb.org (Ti Kan)]

Andrew Pennell writes:
> Does anyone know what function the Aux Air Regulator on an 81 TQC =
> serves. The unit is located on the back of the intake manifold. How do =
> you check for proper operation. - TIA - Andrew 

It's for increasing the idle speed a little when the engine is
cold.  The hoses on each end of this device bypasses the
throttle valve, and it has a little thermal-couple controlled
valve that is open when cold and closes when warm.  There is
a little electrical connection which supplies 12V power to
it for an internal heating element, so after the engine is
started it will gradually heat the unit and cause the air
valve to close.

These aux air regulators are used on earlier CIS cars before
the advent of electronic idle stabilzation that are computer-
controlled.

To test:

1. Remove the electrical connection and test the DC resistance
   between the two contacts on the aux air regulator.  It should
   be read about 30 ohms on your ohm-meter.  If it's not, the heating
   element inside is probably defective.

2. With engine stone-cold, start engine and pinch one of the hoses
   that go into the aux air regulator.  You should observe a slight
   drop in idle speed.

3. With engine running, test that there is 12V DC on the electrical
   plug that you disconnected for step 1.  Be careful not to short
   circuit between the two contacts!

4. If you really want to give the aux air regulator a good test,
   you can remove it from the car, wait for it to get cold,
   then look through it.   You should see a small opening.
   Apply 12V DC to the electrical connection and wait for a
   few minutes.  You should see that opening close.

-Ti
96 A4 2.8 quattro
84 5000S 2.1 turbo
80 4000 2.0
-- 
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Research Laboratories, Sunnyvale, CA. USA
  ///    Internet: ti@amb.org
 //////  UUCP:     ...!uunet!bazooka!ti
///      URL:      http://sunsite.unc.edu/~cddb/tikan/