Desired AFR

[Greenmachine501]

Anyone else having issues logging desired afr? I’m trying to calibrate my Maf sensor and when I try to log my desired afr stays at 14.7 pretty much no matter what. Very inconvenient having to cross reference my tune to figure out where my afr is supposed to be when filling out my calibration worksheet

[Greenmachine501]

Tune and log for reference
2.5L swap, I am new also to tuning so if there's anything wrong with the tune I am open to suggestions/corrections
ignore rpm stutters that is a transmission issue i am working on

[xbrandino]

I don't believe there is an issue with the tune and in fact the car is demanding 14.7 all the time for reasons we are yet to know, maybe your MAF calibration is far off or there is an issue somewhere mechanically on your car.

Absolute Limits:
I notice you are demanding the car to always run in Open Loop meaning no fuel trims are being applied at all times. From personal experience, I suggest returning these back to the stock values. I also recommend lowering your rev limit to around 6200-6500 due to the fact the 2.5 has a longer stroke compared to the 2.3 meaning you don't need to rev it as high and revving it as high as 6700RPM I wouldn't fully recommend. The cams begin to fade from around 5500-6000 in which you have no point to rev past and being the 2.5 producing low end torque shifting very high will cause you to be way past the power band. You should be safe to raise the operating load limits to something greater such as 1.2 from 1500+ RPM.

Fueling:
There is nothing that stood out to me in the Closed Loop tables to be a problem but I have found this engine to produce best power at an AFR of 13.2. Looking at your Open Loop tables, I can see you have changed it around so the car targets different AFRs depending on throttle position, thus you always being in Open Loop, however I do recommend going back to the stock format where all columns match and taper down to 13.2 from around 3000+ RPM. If you are using the injectors from the 2.5 you will need to change your Injector tables to match them, along side volumetric efficiency, cold cranking and after start and warmup enrichment.

Idle:
From personal experience the 2.5 likes to idle a little higher than the 2.3 around the 800-900 range at operating temps.

Ignition:
Obviously nothing has been changed apart from Knock Retard Threshold Min RPM which I would put back to stock '500'. The 2.5 being lower compression than the 2.3 allows for some more advancing across the board. Best power with 13.2 AFRs @ WOT was achieved around 32* of timing at 6500RPM, for me at least. Don't be shy when tuning ignition, there were many times where my engine tanked knock really well, surprisingly, or maybe I'm just lucky. (Use virtual dyno to find MBT and back off 1-2* for safety reasons)

Load Targeting:
I would match all the tables to be the same, ideally make them all the same as 'Calculated Torque - 1' and you can increase the values a little bit more across the board being you have a 2.5, try to set the values to something realistic like 250-280nm depending on what you see.

Sensor Calibration:
For some reason 1 and 2 MAF Calibration tables aren't the same and on table 2 you have a random jump between 3.12 and 3.705. I suggest smoothing that out and match both tables at all times.

Throttle Control:
I see you have lowered some of the values, this is all personal preference but I would've thought you would rather a linear feel.

Valve Timing:
I never really touched this table because the stock values seem to be good enough, although I have heard 31* is a good start and you can increase it a little more around the 5500-6000RPM range. This is one of those trial and error things.

[mituc]

As far as I can see you leaned out the factory MAF calibration for some reason, so the desired always sits around stoich because the ECU reads lean continuously because of the significantly leaner MAF cal (about 10%).
You did not log load in your log, but by looking at the tune and the log you never got out of that area where the desired AFR is what you see in the log both in closed and open loop.

[CrazyCanadian]

APP Thershold 1 and 2 determine when the ECU goes into WOT state.. As a test set them to 105% to keep the car out of WOT.. This should force the ECU to reference the 2 open loop fuelling tables..

I believe WOT has a different fuelling table we don't have access to...

If that doesn't change what your commanded is doing, then set all of your Load thresholds to 1 or 1.1... and keep the app threshold to 105%.. This will force 100% closed loop all the time... You can use that for a short while/don't do a lot of WOT pulls, but a few should be ok if there's no knock issues.. You can use fuel trims at that point to tune your MAF sensor...

I have noticed NC miata's commanded AFR doesn't change... no matter what, but the actual AFR follows what it should do... For that I've had to take my data logs, compile them into something I can put into excel and do manual adjustments..

[Greenmachine501]

thanks for taking the time to go through my tune xbrandino biggest thing i'm unsure about is the injector values i've been searching and i havent found much information on the 2.5L injectors im using (bosch 62405) i saw you posted a tune somewhere else on this forum are you using the same injectors? if so i might steal your injector tables if thats cool.

I'm still working on my maf calibration so its bound to be off i leaned it out that 10% to account for the new injectors having a 10% higher flow rate after accounting for the displacement of the new motor. with the calibration so far im kinda just using it to manipulate my afr tables as opposed to getting correct air mass readings. I also made a mistake and lost my stock base tune so i have nothing to compare with anymore

WOT using a different fueling tabe would kinda make sense. I seem to get strange behavior during WOT as in the car wants to go pig rich on a couple occasions i saw it dip down to around 9.5 AFR, now that im thinking about it maybe that has something to do with my injector settings not being correct. I have it set to run open loop all the time because it stopped going so rich in open loop.

[xbrandino]

Yes, the tune I had uploaded on my other post has the injector scaling for the 2.5 injectors. When I get home later, I'll send you a tune with all the 2.5 tables from a 2.5 ECU which you can copy over to your tune and technically speaking run a stock 2.5 tune and that should get you somewhere.

Are you still running a stock intake? What other mods to you have?

[xbrandino]

I have attached a tune with like promised all the stock values from a Mazda 3 2.5L ECU, however I have modified some things here and there that should benefit you (AFRs, VVT, limits etc). If you are running the stock MAF housing, meaning the stock intake still you should be able to flash this tune no problem and the car "should", and I quote should, drive like normal again. If you are stuck on the side of the road with a broken engine I'm just some guy on the internet (I'm just joking, your car will be fine).

Record some logs for us if you can and try to use parameters like Absolute Load, Mass airflow, Ignition Timing and whatever else you think is necessary.

[Greenmachine501]

Tried out that scaled tune this morning mostly seems like it’s working well getting about 3° of knock retard under load seems to be running a little lean maybe low 14s will post a lot later today as I forgot to hit record earlier. In other news my desired afr appears to be doing something just not sure if it’s following any tables as of yet.

Only issue I’ve noticed is it won’t start when warm without starting fluid. Could be an inconvenient mechanical issue but not sure yet.

[xbrandino]

That’s good to hear, sounds like your MAF calibration is way out and needs major adjusting, you could try add 10% across the whole board and see if it changes anything for starters.

Have you checked if you have any intake leaks that could possibly be causing such a dramatic lean condition?