What does base running airflow do?

[3strokeEngine]

My other thread isnt getting much attention about an issue im having tuning idle on my truck so let me ask in case my understanding of it is wrong

What exaclty does the numbers in the base running airflow table (sometimes called RAF) do?

In some PCMs its in grams per second and on others like the one im working in, its in percentage.

Is 8.00% RAF the same as 8.00 g/sec RAF?

[DougO]

its like adjusting the idle air screw on a carburator

[3strokeEngine]

Then how come increasing base running airflow doesn't open the IAC more?

[DougO]

I don't know why

[Sith]

Because it is corrected to meet target idle. Ideally you turn off these corrections to set the BASE running airflow at that target idle speed. Then use the corrections to stabilize it based on varying conditions.

[3strokeEngine]

Yes thats what im doing. I disable all adaptive idle to try to dial in the base running airflow. Seems no matter what i do to base running airflow the IAC counts wont go over 100 in gear idle.

If i reenable adapt idle after about 5 minutes it will learn the correct idle airflow and idle in gear around 140-150 IAC counts and idles fine.

Seems like base running airflow table has no correlation to IAC position

[Sith]

Post a log and tune and maybe we can help.