Problem transitioing in and out of adaptive idle at light loads

[NJ_Phil]

Car has cam and centrifugal blower. Idle is tuned great where I can keep my foot off the pedal, release the clutch and chug smoothly up the driveway but when I press the accelerator lightly to accelerate, the car hesitates until about 2000 RPM. I believe that's transition OUT of idle. During light deceleration when coming to a stop, If my foot is on the pedal slightly, RPM will drop smoothly until 2000 then stumble and fall under idle speed, almost stall until adaptive idle "takes over", then idle great. If I take my foot off the pedal completely during decell and dump the clutch in just before a stop, it goes into idle perfectly.

My gut feeling says the idle airflow settings are good but the SD table is too lean at very light VE, close to idle transition. The map has super low airflow settings at low VE but I've tuned the map where it's +- 2%. I think Idle airflow is causing the scanner chart to read +-2% but the SD map is lean at that VE and tha "leanness" just gets averaged out in the readings. So what's the best way to properly tune these low VE cells? Maybe disable adaptive idle and see what the AFR error is? Just interpolate VE down from a known good VE?

Not sure if I explained this properly, the wife says I tend to babble but it's the only way I can explain it ;-)

EDIT: I was looking for a scanner flag to show entry/exit into adaptive Idle, would be nice to see that

[schpenxel]

Merged threads/deleted duplicate, haven't read your question yet though

[mowton]

Make sure your VE is tuned properly. While in adaptive idle there is a lot of rpm correction taking place with both air and spark. As soon as you transition above 1 mph and some TPS, you transition to the MAF/VE or Blended mode. The VE's job is to correct fueling during transients. If lean (or super rich) the fueling may not be capable of sustaining the increase in load to move the vehicle.

Log MAF Airflow, MAF Hz, Advance, Dynamic Air, Injector pulse width (both banks), TPS, Accelerator pedal and wideband to see what is happening during the tip-in point that is stumbling.

Ed M

[GHuggins]

As previously pointed out - tune and log and if any mods left out a full detail of the build... Usually when it's exactly at a "2000 rpm switch point" - it's typically a transient issue because that's the full 2 seconds that transients take place from a stomp from idle... It can also be timing too low, but transients always seem to play the bigger role...

[NJ_Phil]

The low VE cells on the map were super lean and getting them in line really helped. Also increased base idle airflow by 20% more and reduced the Proportional and Integral airflow correction table by 50% and idle got even better.
There still is a little undershoot returning to idle which might be the spark ramping down too fast and I'll increase spark to try and "float" it down

There's way too many settings to play with.. LOL

Thanks Ghuggins

[mowton]

The low VE cells on the map were super lean and getting them in line really helped. Also increased base idle airflow by 20% more and reduced the Proportional and Integral airflow correction table by 50% and idle got even better.
There still is a little undershoot returning to idle which might be the spark ramping down too fast and I'll increase spark to try and "float" it down

There's way too many settings to play with.. LOL

Thanks Ghuggins

Glad logging the VE and correcting the lean issues helped....

Ed M

[NJ_Phil]

Didn't realize you also responded... too early in the AM

Thanks Ed