Alfa Romeo Bulletin Board & Forums - View Single Post - Idle Control Valve S4
View Single Post
post #30 of (permalink) Old 11-09-2018, 01:52 PM
But Mad North-Northwest
Platinum Subscriber
Gubi's Avatar
Join Date: Sep 2003
Location: SF Bay Area, CA
Posts: 9,802
Originally Posted by plasmid View Post
But what I don't understand is - why is it Ok with the current settings when warm and not ok when cold.
When the engine is cold you need a more open throttle to maintain the same idle RPM. The L-Jetronic manages this through the AAV, that lets in more air when cold and closes when the engine heats up. The Motronic does the same thing through the IAV.

In both cases, though, the throttle plate (and idle air bypass in the case of L-jet) need to be set right or there still won't be enough air to cold idle.


1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
Gubi is online now  
For the best viewing experience please update your browser to Google Chrome