I have a 1998 K2500 7.4 454 4l80e, with the black box vortec PCM ECU ECM Computer or what ever your supposed to call it.

I Use HP Tuners for it, recently got the Wide Band Hooked up, and reporting with the EGR position pin.

I have found very little in the way of tutorials or write ups on tuning these.

What I have found, states that when you fail the MAF and place it into speed density, it only uses the lower resolution secondary VE table.

I did that and got the secondary VE close enough for me.

SO what I have read is the accepted method, is to copy secondary VE to main VE, and interpolate between.

When I did this, It seemed still way off.

I had taken the aproach that the MAF should be correct as there was no intake modifications, it's stock with stock filter, and clean.
So I have been adjusting the main VE table with the MAF on. Seems to be beter, but i still am having dificulty getting it close in few spots. Light load cruise seems to be leaner than commanded, and decel seems to be extremely rich. Decel was showing around 10:1 I've got it a little better, but still pretty rich around 12:1. At one point I looked at logs to see where the maf was on decel, and leaned it about how much I was off.

I have been doing all this open loop. Closed loop seems to target a little rich around 14.1 - 13.9 on the wide band standard gas scale.
Narrow Bands probably need replaced, but I would rather get it dialed in and just keep it open loop, as that is the only way to use lean cruise with one of these, at least as far as I know.

I have been able to edit the Dynamic Airflow settings and create a MAF only tune, verified by zeroing out both VE tables. If I could somehow use those settings to use Main VE only, I think I wouldn't have any problems. Every attempt has produced no running.

So I am wondering If any one has messed with these much, If so, what was your method?

I am also wondering if I should load a Maf only tune in, and Make sure the Maf is correct, but I am afraid of loosing progress, and I don't want it to get to lean bearn limit and die on the road, I guess I could start by adding 10% to the Whole Maf table to keep from that.

Or just Fail the Maf and run the low res secondary VE?

Am I over thinking all of this?

What what would you do to dial this thing in?