Super noob question, but I can't figure out how to correct the MAF signal (similar to what KFKHFM does). Logging requested vs actual lambda (using a wideband sensor) gets me this under load (graph attached). It starts out richer than requested, but then leans out. I'm assuming this has to do with me upscaling my MAF sensor and upgrading the inlet pipe which would throw off the values, but I can't tell anywhere which map I actually change in order to make the open-loop fueling. Looking at logs, my MAF signal seems to linearly increase with RPMs at WOT, so the sensor appears to be reading at least mostly correctly.

Hardware changes from stock:
Frankenturbo F21 w/ bigger inlet pipe
3 inch VR6 MAF (ported MLHFM over from a Jetta bin)
Cone filter (yeah, I know it's worse for power, but I like the noise and my stock airbox wouldn't fit anyways without a lot of trimming my intake)

Fueling system is completely stock.

From what I've found,
LAMFA controls req. AFR
KFLBTS controls req. AFR above a certain calculated EGT
KFKHFM corrects the MAF signal, but the load axis only reaches 126 (request doesn't exceed 127, but actual load hits 160 at WOT)
FKKVS corrects the injector on time, and isn't defined in any XDFs I can find for my ECU, so I can't change it anyways without finding it

The actual requested AFR seems correct, so LAMFA and KFLBTS aren't what I need to change. FKKVS seems like the best map to actually change the fueling, but then I feel like my load would be incorrect as I think the MAF is just reading slightly inaccurately due to different hardware. To me, it seems like I just need to correct the MAF to get my fueling where it needs to be. Do I edit MLHFM? From what I've read typically it's best to just copy MLHFM when swapping a sensor/housing and then use various correction maps to get fueling where it needs to be.

can't attach a log, nefmoto is telling me the "attachment couldn't be saved", so here is a google drive link: https://drive.google.com/file/d/1ZNzEWKPi7hK-KUGoWdELnz-lxj1VeLud/view?usp=sharing

this is a stock tune with just fueling adjustments, is 8 psi enough to max out injectors/pump? my fueling setup is completely stock (2000 A4 1.8t)

according to audizine the injectors are good up until about 8 psi, which is weird since the OTS GIAC tune this car had before was pushing up to 16-18 psi on the same injectors and running about 11.something AFR, but I guess I need new injectors

do you have any pointers on finding FKKVS? I looked using an 018CH file to compare to and couldn't find the axes duplicated anywhere

still not sure, am I supposed to use KFKHFM for WOT corrections? it seems like it's only really intended to be for part load, and it's my understanding that in open loop I need to manually correct the MAF signal in order to make sure the fueling matches the AFR request since the o2 sensor does nothing (no feedback at all)

I'm a little confused, everything I've found says to copy MLHFM from whatever came with the MAF being used, then to leave it and tune elsewhere. I also have LTFTs disabled by unplugging the N80, as that's what people seem to do in order to log STFTs. How do I "get near zero LTFT" with MLHFM? Do I need to go in and edit MLHFM in the sections with high output voltage?  If I do need to use KFKHFM to correct at load>126, how do I change values above 126 (highest load column)?
I've been using the heatmap to tune part throttle, it's working great.

That makes way more sense, thanks!

Should I reset KFKHFM back to ones, log LTFTs, and scale MLHFM by that much, then repeating until I can get it nearly correct (and my lambda request matches my actual lambda at WOT) then start adjusting KFKHFM?

Also, since it looks like I need new injectors, and I don't want to clog the forum with even more new topics, could you point me in the direction of KRKTE on my ECU? My definitions all seem to have weird scaling and locations (scaled by 0.002133, and when set to 0.000111, the value is 0.0057 which seems wildly incorrect compared to other files I've explored). I can't find FKKVS either so searching based on being located close by wouldn't help.

I'll try and get a log with injector duty cycle, are there any other variables I should log? To my knowledge the fuel rail pressure isn't logged so no way to know without hooking up a physical gauge. Should I be looking for injectors >90%?

I started with KFKHFM mostly zeroed, at some points I've needed it to be ~0.8 to get it to the correct AFR

it seems like the entire map is running rich, maybe there's a chance that the MLHFM from the VR6 file was somehow wrong, should I take the advice of someone else and try using the original MAF sensor in the new housing and scale it (like what I see most other people do) and then see what results that gets me?

YES 100% this.

Note that you should throw out all data points where your injectors are above, say, 70% DC


Do NOT touch injectors until you have KFKHFM in a good place. You don't want to be mapping both MAF and injector changes at the same time.

are you sure it is going rich and not idle torque res? if so, yes, at very low loads, if you ditch the airbox you'll see all sorts of wonky MAF nonlinearities. This is why airbox is the best for drivability.

Sort of.. KFKHFM is more for steady state fueling with very slow RPM/load changes. If you are going rich off throttle, thats a different map (decel fueling) since it's a sudden change in RPM/load