Going rich then lean when shifting

[dleach1407]

it also factors in the short term fuel trim as it shows the fuel error

So do I want my MAF error to be between 1 and 1.03 or do I want my LTFT at 1 to 1.03.

[decipha]

thats the same thing

[dleach1407]

OK, so i have an update regarding the issue. I dont believe the manifold volume is the problem. When I stab the throttle in neutral, it goes rich, When i roll into the throttle it has the lean problem so I dont think the manifold volume is causing the issue. I am pretty sure the manifold volume needs to be reduced since its hitting 12:1 when i stab the throttle. Ive read a few threads on eectuning.org that refer to the load w/ failed MAF table (fn1036) as the cause. Should I start looking at dialing this in? If so, any writeup or advice regarding that?

[decipha]

no that means it has to come up

histogram will dial it in for you

[dleach1407]

I meant increased not reduced, not sure why i typed reduced. I now see how i can dial that in. \

Edit, Found the histogram.

[dleach1407]

I was reading a thread on eectuning that you had replied in regarding a similar situation that I am having. What he describes is what is happening with my car.

https://eectuning.org/forums/viewtopic.php?t=16787

Your recommended solution "if i had to go out on a limb here i would say your decel enrichment is pulling out too much fuel and as you tip in your big time lean, coupled with a lean spike there's not enough fuel to prevent a buck or hesitation

If I understood you correctly, you'll probably fix the problem by removing the decel transient enrichment, go set the scalar multiplier to 0 that way it doesn't pull fuel as load comes down"

Is there something in CBAZA similar to this I can try? Im trying to find as many things as I can to try and look at this weekend when i get time to try and finally get this fixed. I will be increasing the manifold volume until i get a fairly stable AFR when stabbing the throttle with neither lean or rich spikes. From my understanding 15.5 is what i should be hoping for when stabbing the throttle in neutral. After I get that where it needs to be im going to play with fn1321 to see if it makes any difference.

[dleach1407]

did some messing around with manifold volume and increased transient fuel in fn1321. The issue seems to be improved but also worse at the same time LOL. So before when warm, it would drop to say 16-17 afr when shifting but would be slow to recover. Now, it drops to 18-20 afr but recovers almost instantly and I didnt notice the slight hesitation I normally get. Manifold volume is set to 6 and I doubled 1321n however most of the cells are maxed out at 0.0623 so I think i may need to return those back to original and go higher with the manifold volume. I dont know how it runs when cold since i cleared KAMs and im still dialing in the maf. Since i am having an issue with getting fuel dialed in due to fuel heat, Im doing 30 minute drives, making changes, letting the car cool down and then do another 30 minute session to try and maintain constant fuel density. This should replicate tuning sessions close enough that I can get it close and call it good. until I go to a smaller main pump im always going to have inconsistent fuel errors.

[PaulC-turbo5.0]

What you describe is exactly how mine is now as well. Once i clutch in it yanks the fuel but when I come out of a shift it’s right back to stoich right away every time. It did take me a little a bit to get used to it shifting though. This has helped a ton when cold though so hopefully it does with yours too. I also have my CL delayed to 180 secs. My 1321 table is also doubled and guessing the same cells are maxed, if it works good cold I’d leave it.

[dleach1407]

What you describe is exactly how mine is now as well. Once i clutch in it yanks the fuel but when I come out of a shift it’s right back to stoich right away every time. It did take me a little a bit to get used to it shifting though. This has helped a ton when cold though so hopefully it does with yours too. I also have my CL delayed to 180 secs. My 1321 table is also doubled and guessing the same cells are maxed, if it works good cold I’d leave it.

Mine doesnt seem to pull fuel until right after i press the throttle as engaging the next gear. Maybe the lean spike im seeing is it actually going lean from the throttle snapping closed/tip out. When i press the clutch in and the rpms are coming down, the afr is in the 14/15 range as far as I know ill have to pay attention to that. As soon as I press the throttle and let out the clutch, I get a fast dip down to 20 then right back to normal AFRs. I mean its fast, probably less than half a second. Hoping there is a way to extend how long the enrichment occurs for. If i could get another 500ms, I think it would be gone. I found another thread recommending playing with FN1052 to lengthen the enrichment time but I cant find any other info about it. another thing I changed was the hego switch voltage breakpoint. I saw in the new a9l2 its a recommended setting for longtubes. Well my o2 is further away that it would be with longtubes so i set it to .3v instead of .425. The switching seems to be much faster, maybe im just imagining it.

[dleach1407]

moved the manifold out to 8 and i am still getting the really lean spike. it is still there when its cold as well but its not as bad as it used to be. What i am finding is when in neutral when warm, if I stab the throttle, its still going rich but then as it comes back down it goes really lean. Im wondering if there is a decel function i can adjust so its not pulling out so much fuel as the rpms decel. Should I keep moving the manifold volume?