HELP! Lean spot in cruise. Cylair drops, goes lean

[Jays68yak]

Been struggling with this tune the last few days. 6.0 iron block, bored .030 over, flat top pistons, 243 heads, cam, springs, flipped truck intake, 8.1 marine injectors.

First it was the injectors but I think I have them figured out.

I thought I had the VE and MAF pretty dialed, started to check WOT and I noticed a lean spot while holding around 2k in 2nd gear (on chassis dyno with 21% load). Best way I can describe it is that the cylair drops and then I get a lean spot, and p0101. Ive tired upping the VE table by about 10% in the offending area. Also added to the MAF table in the same general area. Tried different MAF and removing air filter that we thought might be restricting.

Thoughts? What am I missing? What did I do wrong?

2004 yukon 60 12587603 help.hpt
help.hpl
help.jpg

[5FDP]

Just from looking at the MAF curve and VE, they could use more work. That MAF curve is not smooth at all, needs to still have a factory like curve to it.

Those fuel trims are pulling fuel out nearly 100% of the time once you get to speed, -18% again showing more fine tuning is wanted.

When tuning both the VE and the MAF are you making sure to seperate the two, as in failing the MAF in the tune with the correct settings and removing the channels to prevent skewed data. Then with the MAF putting it into a "maf" only by setting the dynamic airflow to a really low rpm like 200.

[Jays68yak]

Just from looking at the MAF curve and VE, they could use more work. That MAF curve is not smooth at all, needs to still have a factory like curve to it.

Those fuel trims are pulling fuel out nearly 100% of the time once you get to speed, -18% again showing more fine tuning is wanted.

When tuning both the VE and the MAF are you making sure to seperate the two, as in failing the MAF in the tune with the correct settings and removing the channels to prevent skewed data. Then with the MAF putting it into a "maf" only by setting the dynamic airflow to a really low rpm like 200.

Correct, but then I changed the MAF curve after a few WOT checks and AFR correction.