two lc-2's V8 afr imbalance

[dll67]

Update ...

After some fine tuning of my afr table, injector trims and trial and error with the ego delay table, she's starting to run smoother and the afr imbalance is much better.
Afr imbalance is definitely tied to my injector trim settings / airflow characteristics of my intake manifold. The closer I can balance egt temps at different map/rpm areas the closer afr gets.
Bucking and surging seems heavily tied to the ego delay table and ego response time settings. My Ego delay table is sensitive to map and rpm bins just like my VE table. I am having trouble getting the cell settings in both to be right for acceleration and cruising states. I'll try adding more resolution to the tables in those trouble areas.
Does anyone have any information on "ego delay table" settings? Documentation on implementing it would be awesome. Extensive searching of the manuals and the internet have really only turned up that "the newer alphas have a 2.55 second max delay now a factor of 10 has been applied to it".
From http://www.msextra.com/forums/viewtopic ... 52#p445752
Thanks Dave

[dll67]

Another update....
Still can't get the afr's to stop hunting for balance running a Hilborn it's with the injectors mounted low and inside the runners. The injectors inject into the ports directly at the back of the intake valves.
I'm thinking the ego sensor response time (ms) needed verifying. I'm running the delay around 85 ms .. I'll try varying between 77 & 93 ms.
I'm running my wideband sensors on the can bus through a can-egt box.
I've gotten the map signal steadied well now and the timing and ve tables smoothed to minimize their causing the hunting.
More updates to follow

[jonfx4com]

I had some success with this problem by using dual table with one VE table per bank and a single AFR table. There has been some argument that this is not possible but this seems to be based on misunderstandings and it seems to work perfectly on my strange odd fire V8. VE1 is my left bank (odd) and VE3 is my right bank (even). I use Inj ABCD for odds and EFGH for evens and use bank fire (MS3Pro Evo). I guess it may not work with sequential as you would need to associate each injector with the correct VE table, but I never tried so I don't know for sure.
Set dual table with no switching and then you can tune each bank to overcome the differences in airflow between the two inlet tracts.You can also use autotune separately on each bank to get the VE tables approximately correct and then tweak them by hand if necessary.
You can then turn of trim tables as you will not need them.
But as I said, I don't know if this method can be combined with sequential where the order of the injectors is not so simple.

[Keithmac2]

One VE table per Bank sounds like a very good idea!.

[Six_Shooter]

Why not just use injector trim tables? You can do individual cylinders then.

Using separate VE tables per bank seems overkill and would make tuning more involved.

On that note, how did you associate each table to each bank of injectors?

[jonfx4com]

in dual table the VE tables default to ve1 bank 1 and ve3 bank 2.
On ms3pro (not sure it’s the same on ms3) bank 1 is inj ABCD and bank 2 is inj EFGH so in bank fire it’s quite straightforward. You then associate ABCD with one EGO and EFGH with the second EGO. In autotune you will then see two separate tabs for ve1 and ve3, and you can tune them both at the same time.
No big complications, it just works.

[rickb794]

Maybe your ve tables need work, so it is not so dependent on O2 correction?

Where are your LCs grounded?

They are configurable.

I assume you have swapped stuff around to prove there is not a hardware issue. 1 leaky injector, or 1 lazy injector, or bad driver.

[BlueCuda]

I have fought the same issue, I have a 418" motor with a port injection tunnel ram and a large solid roller camshaft. The drivers side bank was always leaner at idle and part throttle cruise. But once you start to get some throttle and RPM they evened out nicely. With a large camshaft and an intake meant for higher RPM the distribution is a mess with fuel blowback during overlap etc. I have tried lots of injector angles and nothing seems to really change it. It runs good, starts good, makes power so I quit worrying about it. This has been an interesting read though I might need to revisit!