Why is my MAF tuning not working right?

**Fastmax32168** · 07-13-2023

I am hoping someone can enlighten me as to what the problem is with my current project and getting it tuned correctly.
I have installed a 6.0 with 243 heads and a mild cam into a 91 K1500 pickup.
My initial attempt has been to dial in driveability with the Factory 02 sensors and Long term trims, as it wasn't reading as being too far off when I first fired it up.
I turned off everything MAF and used these factory O2 sensors with a Histogram I created to dial in the main VE table and it runs and drives pretty decent that way.
I then turned off everything MAP related and went to dialing in the MAF sensor.
I created a histogram using Long term trims and MAF sensor Hertz and here is where it went sideways. I want to understand what has gone wrong.
The trims started as under 10 and after a few tuning trips I have them dialed in really close. Most are under 3. But it seems like the closer I got to optimum the worse it runs. It hesitates, pops, bucks, you name it, it just runs badly.
My current plan is to put my wideband on it next and see what the AFR actually is this way, but I am really wanting to understand what I have done wrong here, and why this method did not work, as I have used it before multiple times with no issues.
Thanks,
Roy

**steveo** · 07-13-2023

lets see your original maf table vs your new corrected one

**Fastmax32168** · 07-13-2023

Originally Posted by steveo

lets see your original maf table vs your new corrected one

Thanks for the response. I am really not sure how to accomplish that Steveo. Be happy to try if you want to give me a tutor. I can tell you however that they are not much different. Other than smoothing out a few little wiggles from the original one there is not much changed. It almost looks like two dyno runs from the same motor laid over each other with only very minor differences. Honestly it doesnt run well with either one, although the trims seem to say that it should.
Roy

**Fastmax32168** · 07-13-2023

Originally Posted by Fastmax32168

Thanks for the response. I am really not sure how to accomplish that Steveo. Be happy to try if you want to give me a tutor. I can tell you however that they are not much different. Other than smoothing out a few little wiggles from the original one there is not much changed. It almost looks like two dyno runs from the same motor laid over each other with only very minor differences. Honestly it doesnt run well with either one, although the trims seem to say that it should.
Roy

let me try attaching the two tune files. maybe something else is screwed up,