Controlling lambse on decel

[canuck1]

CT decel load at 3000.jpg

OK, I guess I'm going to need to review what to do. Here's a pic of dashboard at 3000 rpm, closed throttle decel, .071 load. It does look a lot like my injectors almost shut off at decel.

Sean

[PaulC-turbo5.0]

just to follow up on my end I did go double check and as expected the patch for this has always been enabled, I am using the most up to date files. After enabling fn338 I have been very happy with how it decels in OL that I have not tried to mess with it again.

Like canuck just said above my injectors almost shut off on decel so the WB goes lean and lambses ramp rich. Is the goal to try to maintain stoich on decel? If so I was going the wrong direction with the airmass correction table as my focus was trying to correct after the decel

[canuck1]

Paul,

Just to confirm, you never went back and adjusted FN1035 to allow for CL decel control? You only made changes to FN338, which is effectively an OL adjustment and its working fine for you? You haven't found a need to go back and 'dial in' FN1035?

Sean

[PaulC-turbo5.0]

No I have not gone back since enabling fn338. I can decel and downshift as much and as long as I want and once I’m back on the gas pedal it’s right back to stoich every time. No more dipping rpm’s and surging either.
Before doing that I changed the whole right side of the fn1035 table to as low as .5 and it seemed to make no noticeable change.

[canuck1]

Thanks!

Have you seen any case of going rich on decel?

I saw a couple of your FN338 suggestions here but am struggling a little to understand how you settled on .17 as your sweet spot? Is that essentially "just over your decel value" and enough to keep it from struggling to find stoic when you come to a stop? Which rpm values did you change and which did you leave alone? Is everything above 3000 rpm just assigned a load of '1.0' ?

I'll try it once I begin to understand it more.

Sean

[PaulC-turbo5.0]

no my WB almost always goes full lean on decel which I think is DFSO

.17 is the load where it will go in and come out of OL. When I originally set it to .14 like Decipha suggested I had a few instances where it wouldnt go in OL on decel. I then changed it to .2 and it would go into OL easily on decel but then I had a few times where when I got back on the pedal in a real light cruising state and the load didnt get high enough to kick it back into CL which made me finally land in the middle at .17.

Go to an earlier post in this thread where I posted a screen grab of fn338 to see how I have it setup. I essentially have it set to .17 load at all rpms so anytime I decel in pops into OL

[canuck1]

Thank you. I really appreciate you taking time to share your experience.

If I understand the logic behind FN338, it doesn't keep you from going lean, just forces OL to prevent Lambse from ramping rich when its in decel state? And in your experience, this makes the transition from decel-stop (idle)-accel smoother?

I know what DFSO is but I haven't specifically enabled it to my knowledge. Is it possible its the default status of current version A9L2? I don't remember my car sounding like it does now under decel (like fuel has been shut off) using earlier A9L2 versions, but I could be wrong. It works well for me, since even a small amount of fuel available at decel makes my car pop like a squadron of Harleys due to the short exhaust config.

I'll make some changes to FN338 to se if I can improve the only real issue I've seen so far. Otherwise, I'm really happy with how its working.

Thanks again!

Sean

[canuck1]

Is this similar to your current FN338?

I opted to start with a lower number than yours mostly because its between what you ended up with and what Decipha recommended. I'll adjust from there.

Sean

[PaulC-turbo5.0]

No problem man Im glad to try to help

Yes thats exactly correct. Thats where I end up confused about leaving it in CL.

I have not enabled DFSO either and not sure if there is any indication if its actually doing that or not but the way it behaves seems like it is. I am also very happy with the A9L2 settings and even more-so now since enabling fn338.

Yep that looks very close to how mine is setup so it should be pretty easy for you to get it dialed in. Good luck with it and come back to let us know how you make out.

[canuck1]

OK, so I uploaded the changes to FN338, made sure patch was applied and the changes didn't seem to work for me.

I thought that in those decel ranges where load dropped to .16 or below that I would see Lambse pause, remain at 1.00 and OL indicated on the dashboard. None of those things happened. Any idea what i did wrong? I have some other electrical gremlins going on right now, so that may be playing a part.

Sean