Sag/dip when entering idle

[Hodgdon Extreme]

Turbo 2JZ with a Bosch 68mm DBW throttle. Got the idle base position calibrated; it needs about 2.5% TPS to idle when fully warmed. Idles great. However I've noticed after an overrun fuel cut, approaching a stop - RPM will sag to about 500rpm (which is 400 under target) as soon as I pull transmission out of gear. Then closed loop idle control would swoop in and prevent a stall. Then it would idle great again.

After studying the log files, I noticed during the overrun, and as the ECU was preparing to enter closed loop idle mode, the E-throttle target was 0%. Only after closed loop idle mode is active does the E-throttle target go to it's base position of ~2.5% - creating a moment where there isn't enough airflow to maintain proper idle.

The 0% APS breakpoint on my APS vs. E-throttle target table WAS set to 0% APS = 0% TPS

I changed that to 0% APS = 2.5% TPS (same as my idle base position percentage)

This solved the RPM dip, but it doesn't feel like this was the correct way to do it.

Thoughts/suggestions?

I can post cal/log files if helpful.

[Vaughan]

Sounds like you might not have enough dashpot offset or your overrun fuel cut off RPM is too low. Attach your basemap and a log please.

[Hodgdon Extreme]

Calibration file:

https://drive.google.com/file/d/1n-l2PmigFlgAVKPX8fHQC63Qe6jfFLmu/view?usp=drive_link

Log file (there are the dips I'm talking about at 9:08 and another at 10:08):

https://drive.google.com/file/d/1BgU5tLseQYaOjkd4RQ1TfdfTfA-ovW6A/view?usp=drive_link

PS: is there a way to crop a log file down for instances like this?

[Vaughan]

I would recommend changing your idle RPM Lockout Above target to something more like 500RPM so it only enters idle control once it's much closer to the idle RPM and so doesn't have time to wind out all of the base position with the integral. I would also recommend an APS lockout of something more like 0.2% or 0.5% and an idle Min clamp of something more like 2%.