P Mack

iTrader: (6)

Does the IAC adjust to keep a constant idle speed or a constant idle airflow? For example if i were to change the idle air tables to like 20 g/s would the engine rev up?

gameover

It tracks RPM and dynamically adjusts an airflow value that eventually controls the IAC motor or the ETC.

if you set it up to 20, the dynamic adjustment would pull it back to the idle RPM. The idle control for the IAC has the equivalent of a fast learn and slow learn (kinda like STFT's and LTFT's) and it remembers the last position the IAC was in under the various combos of PN/Gear/ACon/off (again kinda like the fuel cells).

In my own private "let me break stuff" version of our s/w i have full visibility of all the airflow components that make up the final idle airflow that drives the IAC. It takes a little time to get all this into the scanner since very few of these parameters are available via GM PID methods and it becomes custom per operating system. That reminds me i think i said i would post a detailed description of the Idle airflow a while ago...

In future look forward to "I got my idle trims at -0.8, what next?"

Hope that helps.

P Mack

iTrader: (6)

lol
Yeah that helps a lot, thanks. So by the components that make up the final idle airflow do you mean like throttle cracker, throtte follower, and "idle trims"? If you could post kind of an explanation of how those work together that'd be really helpful even without the ability to log them.

Bink

Gameover,

Yes, it helps.
Can you post the relationships of the Throttle Followers(Decay Tables), Idle Air and IAC Park - for ETC ????. Are the Airflows identified by the Throttle Follower and Throttle Cracker tables added to the Idle Air value?? What are all of the values that make up "Final Idle Airflow"??

joel

gameover

yeah gimme a few days to translate my gibberish txt file on how this works into something that resembles english.

Bink

English is good. Thank you.
joel