Any way to scan Desired Idle airflow?

[Highlander]

For the E38?

Or is there a formula to convert idle airflow into tps?

[swingtan]

I guess it depends on what you are trying to achieve, but I don't think there is a specific pid for "commanded" air flow. You would need to know this from the set values in the tune file.

And what do you mean by TPS ? If it's Throttle Possition Sensor, then no. You can't get an air flow from a throttle possition. You can get an airflow directly from the MAF or calculate it from gm/Cyl in SD mode.

Simon

[Highlander]

I know that... but you can have some sort of correlation as to what TPS will correspond to the amount of airflow you are seeing. The point is to be able to determine when you have too much minimum idle airflow that is affecting your big cammed driveability.

[swingtan]

To check if there is "too much" idle air flow, I go by...


If the RPM's "hang" or "rise" when lifting off the throttle, especially between gears (M6).
If the car drives it's self on a gentle down hill slope.
if the logged commanded idle spark value is lower than the idle spark value set in the tune. which indicates that idle timing control is trying to pull the idle speed back when there is too much idle air.


Simon