ISV Questions, 1988 90q (longish)

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

In message <0716D052C1CFD0119D280060979FBE9A4991@a1.matrix.com.pl> Aleksander Mierzwa writes:

> I wouldn't trust anyone who adjusts %CO not using an exhaust gas
> analyzer. I also doubt if the oxygen sensor has any effect on ISV valve.
> That's what the frequency valve is for. I may be wrong, but that's my
> opinion.

Amen to that.

The idle and CO adjustments are _separate_ but interdependent.  For my car (non-
OXS open loop) the instructions are to set the idle with the engine warm, a/c 
off, all electrical loads off, battery good, and go for 430ma through the ISV 
at 800 rpm using the idle screw on the front of the throttle body.
 
If the CO is _way_ out, you won't be able to achieve this.  Moving the CO will 
affect the idle settings, but that _doesn't_ mean that this is a way to adjust 
idle.  The initial setup of the fuel metering system is long and complex but 
not difficult - it involves setting the actuator roller at 23.1mm below the 
fuel metering head mounting flange, etc., etc.

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club