No control over IACV when cold

[Neo]

I am running out of ideas here. It seems like I have no control over iacv when cold.
Symptoms:

- idle rpm is way below target, should be 1500 but actual idle is about 850-950
- idle learned value stays at 30% no matter what I do to the idle % vs target table, I can go exterme either way with no effect
- it seems to me like iacv doesn't open enough on startup, a slight tb opening improves engine start by a huge factor

All of these symptoms go away when everything warms up for about 10 min, idle rpm is on target, idle learned is at about -5%, changes to idle % vs target table affect idle speed and idle learned value.

Hardware: 01 Prelude, 1020 and Euro R H22. Coolant lines are connected to iacv and there is coolant present at iacv.

What do you guys think it could be ??

[PQatPIT]

In AEMPro see: Idle -> <<Advanced Idle >> -> Options - Advanced Idle. Sounds like there might be Idle FB Maximum 30%, and in your case it is too small.

[Neo]

You could be right, I will give it a shot tonight. Right now I my Idle FB set for +/- 15%.
 
What Idle FB numbers work for you guys ??

[shaundrake]

I have mine at +/- 10%. If you need more than +/-15% then your idle isn't tuned properly. It's going to overshoot the target all the time.

[Neo]

When I tuned my idle, I followed idle tuning procedure in the user guide. I set my idle learned to -5% accross the band. With headlights on, rad fan running, foot on brake etc, it sits at about -1/-2 %. I couldn't get my car to idle below 675 rpm. Normal idle is set to 750 rpm.