Help with AFR swings during throttle transitions LS1 in track car - causing concern.

[Danny Cabral]

So with a target idle RPM of 950 is the following for the first 4 cells good? 750, 850, 950, 1050?

Yes, that's perfect. Then "Fill Row Values from 1050 to whatever RPM your last redline cell is.

Or would it be helpful to set the scale lower or higher before and after the 3rd cell?

Nope.

BTW, I appreciate your help and will go back and rebuild my GF making sure I use all of this information and suggestions in the link you provided.

You're welcome.

[LS1Z3M]

I rebuilt the GF (attached) with the MAP scaled correctly based off an older version.
rebuild.zip
The engine started, idled and revs fine. Although it has not a lot of time to Learn the wide AFR swings are still clearly evident mostly when coming off throttle. Otherwise the AFR is stable and looks fine. DL attached.
07111505.zip
Is this an issue or is this not something I should worry about? If it is a problem, then I'm really scratching my head on how to fix it, as is the engine builder who has been using the Holley EFI systems since they came on the market,

[81 TransAm]

The engine started, idled and revs fine. Although it has not a lot of time to Learn the wide AFR swings are still clearly evident mostly when coming off throttle. Otherwise the AFR is stable and looks fine.

Why worry about off throttle. In deceleration, it won't go into Closed Loop, so it will never Learn these areas. If going lean on deceleration bothers you, raise the Minimum Injector Opening Time setting. If all your going to do is jab the throttle on & off it will never Learn. Long steady pulls will get it to Learn, then you can reduce the Closed Loop & Learn Limits to lock in the tune.

[Danny Cabral]

Or manually tune the Base Fuel Table in the deceleration area, that's what I did.

[LS1Z3M]

Why worry about off throttle. In deceleration, it won't go into Closed Loop, so it will never Learn these areas. If going lean on deceleration bothers you, raise the Minimum Injector Opening Time setting. If all your going to do is jab the throttle on & off it will never Learn. Long steady pulls will get it to Learn, then you can reduce the Closed Loop & Learn Limits to lock in the tune.

Full on/off throttle is a necessary and desirable function of track driving that can't be avoided. The DL file I attached was just an example, but the same thing happens on track. I'll check into adjusting the Minimum Injector Opening Time setting.

[LS1Z3M]

Or manually tune the Base Fuel Table in the deceleration area, that's what I did.

We've been trying this approach with minimal results since the events can happen at any RPM.

[81 TransAm]

Full on/off throttle is a necessary and desirable function of track driving that can't be avoided. The DL file I attached was just an example, but the same thing happens on track. I'll check into adjusting the Minimum Injector Opening Time setting.

Do the Learning with long steady pulls, then lock the tune in, then you can jab the throttle all you want.

[LS1Z3M]

If going lean on deceleration bothers you, raise the Minimum Injector Opening Time setting.

I checked and this is currently set to 0, do you have a recommendation for a value I could use as a starting point? Thanks for the support.

[Danny Cabral]

I checked and this is currently set to 0, do you have a recommendation for a value I could use as a starting point? Thanks for the support.

I use 1.00 msec Minimum Injector Opening Time.

Do the Learning with long steady pulls, then lock the tune in, then you can jab the throttle all you want.

Yeah, like this: http://www.youtube.com/watch?v=qwkqjotkDJQ (Holley EFI Learn/Self-Tuning Demonstration)

[81 TransAm]

I checked and this is currently set to 0, do you have a recommendation for a value I could use as a starting point? Thanks for the support.

I use 1.8 msec because I don't like popping on deceleration. But as long as you are below your idle & cruise IPWs, you can use anything you want.