[Tor]

Originally Posted by Kodename47

@Tor as you haven't changed the injectors doing the PI/DI separately is probably not worth the effort. The issue is that the DI fuel system runs at different pressures when fully used to when switched off so you can't tune it for just fully on or fully off. The PIs are also the limiting factor, not DI.

Since my stock tune, I had issues with my LTFT. Especially with the stock injector ratios where at 5000 rpm port injection come back at 20%. This usually caused a huge split in LTFT once the ECU started learning (different tunes, different MAF scales).

Now I am running an adaptation of the K00C injector ratios with 20% port injection from 2000 rpm and have good flat AFR and a uniform LTFT throughout the rpm range. Only I'm annoyed that the LTFT is so inconsistent causing the AFR to swing up and down.

I am just wondering if the problem could be this:

Originally Posted by jamesm

I actually apply this process even when tuning cars with stock fuel systems, because I've found the stock calibration to be imbalanced by as much as 10-15%, and at that point there is a drivability win associated with correcting it.

I should add my car runs great. It never ran smoother, I run a large amount of timing and it feels extremely powerful and willing. However, with LTFT up to +4.56, it runs in the low 11s or even slightly below. I suppose I could just ignore it and enjoy the way it drives but I am curious if there is a way to correct it. LTFT fell back to +3.76 during the last drive. It's almost as if it's responding to the way I drive too, lot's of WOT and the LTFT goes up. Drive like a grandpa and the LTFT falls back down. Could this be because it sits in different cells and with different injector ratios where the LTFT is set and again because the port and direct injectors are off of each other?

Back to the MAF:

4.2/4.25v would work as the MaxV, I leave the OEM minimum and the min unchanged should be the lowest voltage you see.

The value in Vgi's tool is called max unchanged and is required to be above "Min V". If I set a value lower than 2.5 it produces weird results. It even created cells with negative voltages in some cases of low values. Could there be a bug in there? Or did Vgi make a wrong implementation somehow if it really should have been "min unchanged" and not "max"?

I now calculate a new ELC table using the same data as adjusting the MAF, kills 2 birds with one stone.

Do understand correctly that you mean I could leave the MAF as it is, and use a "MAF scaling log" to instead make adjustments to ELC? And that this would reduce the fuel trims in CL and hence make my LTFT in OL smaller?

Also, if you're really that bothered about the MAF, set all your open loop fuel target to one value in the region of 12.5-13 and that way you're not chasing a changing fuel target.

You mean to do this for the MAF scaling only?

Thank you so much once again!