Idle speed is not stable, 90Q

[vjokic@iaw.on.ca (V. Jokic - Push)]

Well,  I am realy wandering why my Audi  brings another problem evry day.
Should I try to please somehow audi Gods? Today, my idle speed (that was OK
for a month since I have this car) started to go unstable and depends on
engine load. If I switch air ON, idle RPM drops from 800 to les than 400!
Head lights will drop RPM for about 100, rear defroster for 200, etc. With
less than 400 with air ON, it is almost impossible to drive this car.
Could someone give me any idea what to look for? This car is completely new
for me, I even do not know where is ISV located. No repair manual. I have
tried to pull oil dipstick out, so it makes additional RPM drop, if air is
ON, without dipstick no more than 300 RPM! Please help.

Thanks for any input.

Push  

root