What is typical increase in IAC counts with PE and AE I see mine jump to 50-70 range is that too high. Tuning the IAC idle is fincky. It responds much better when IAC is low. otherwise there is throttle lag

 

I'm not saying mine is normal, but I've seen 130 on data logs. No a/c it idles at 30. A/C on at idle, 80 or so

 

Yes I have seen that as well. WHat I found as I have tuned in the IAC. That if my Throttle Plate, TP, is closed too much the IAC has to make it up and I have high IAC counts like 20-30 at cruise in drive then it feels in AE the IAC responds but since smaller then slower then the TP plate I get some bog. If I just open the TP up after my tune like 1 full turn the IAC come down into 14-10 range (I have to tweak the TPS then since it goes up) and it feels better.

I was just wondering what others see? And I have noticed when I hit PE the IAC spikes to some flat line number as well. It seems like 50counts higher then idle and it flat lines across the PE run? Is this controllable? Could this be adding to some lean and knock? Is there a table to control it?

 

As you can tell, I'm a noob at this, however I would think the IAC is out of the picture control-wise at anything above idle except as you say at cruise, where it should be open in anticipation of a closed throttle event to prevent an overly rich/lean condition on deceleration. Smarter people than I will know the answer to this.

 

I agree. But from multiple runs and AE testing if the IAC has to open more at tip-in for AE then I notice it is not as responsive as when it is not needed as much.

 

The AE difference probably has to do with the delta TPS. If the IAC is open more, then there is less throttle opening off idle during normal driving conditions. A throttle "stomp" however, should be insensitive to the IAC as its a relatively small effect. Depending on the ECM in use, there are AE terms for the IAC as well if I recall, but not all ECMs will have this.

Off idle the IAC is controlled by the throttle follower logic. This commands some IAC opening so the RPMs dont fall as quickly after the throttle is suddenly closed, and also maintains a higher idle speed during drive. Both help the idle logic better control the idle.

Edit: For a MAF car, it will be more sensitive to throttle transitions since the MAF cant see the inrush of air into the intake (un-metered air), hence the momentary hesitation. Best thing to do is set the IAC roughly where you need it, and then tune the delta TPS AE to get rid of the off-idle flat spot.

 

Dimented24x7 I agree with you. I think 1: I was starving for fuel I will go fill it up if I take 10 gallons I know my fuel gauge is acting up and 2: I hate this OEM replacement pump it is too sensitive to tank volume I need a better one that flows all the time unless bone empty.

I checked my bin I did lower the TPS% to AE from 4% to 2% and the TF follower was set at 5 versus the stock of 10. So like you said I have been tweaking my tip in to compensate hence bogging then decel been hanging. I will put AE back to stock and maybe bump TF to 7 and open my throttle plate a 1 turn so I am not having as much IAC at cruise.