The cold IAT might have something to say about LTFT subtracting fuel. You could try doing some pulls in warmer temps and I wouldn't be surprised if your LTFT go up slightly.

That would only make sense to me if the iat compensation table exaggerates in its current form. Else the ecu should add fuel to compensate for higher air density, if it's cold.
Nevertheless, comparing the actual log to an older one with similar ambient temps (where ltft was zero nearly all the time), I'm pretty much certain that adding the 70% pfi at low loads exposed the pi<>di proportion is off.

I didn't care about going full di when I calibrated the maf scale back then. :-/

Interesting. Perhaps fuel quality may have something to say about this as well. :iono: I'd like to know how much difference your PI will end up compared to a maf scale dialed to 20*c (68*F) in full DI where the IAT compensation is 0 on the stock temp compensation table for the entire range. That's if you want to be as anal as I am with this thing. My previous MAF scale was dialed to much warmer (also varying temps. higher on the lower end of the scale. particularly idle, and off idle speeds) temps since the average ambient temperature around here is pretty high compared to where you're at, I'm assuming. I was seeing about a 6% average difference in fuel trims in CL between DI and PI. Of course the difference was not linear, though predictable.

Edit: after changing the Port injector flow scaler to -6% from stock fuel trims have gone too far in the negative above 2.0v and also below 1.7v MAF. Will go back to a higher number for the port injector flow scaler. May have to look into getting something that will log the PI and DI injector quantity and adjust there as @Kodename47 suggested to really nail this down.

This was the amount of error with -5% value from stock
https://scontent-lax3-1.xx.fbcdn.net...20987960_o.jpg

This is after changing the value to -6% along with small changes to IAT compensation. (214.xx vs 216.xx)
https://scontent-lax3-1.xx.fbcdn.net...89507272_o.jpg

I think I'm probably spending too much time trying to "fix" things and it's backfiring.:bonk:

Small update: After casual driving for a couple of days, I decided to go back to full-DI in the 0.2 load column. It doesn't feel very well.
My assumption is that the intake air suction at low rpms is too weak to get the mixture dispersed enough.
That's my only concern for now, else the car feels great! 👍
http://images.tapatalk-cdn.com/15/12...e1ca40b5d9.jpg

Richer in closed loop?

I think you need to google "closed loop" again.

Sorry, English is not my native tongue. Of course AFR is always around ~14.7 in closed loop. What I meant was getting the injectors to inject (lol) more gasoline, thus getting trims back to zero.

After a couple of tests settled on ratios as below. Made the 3200 line 100% DI as this is arround where the last ltft correction is done (maf arround 3V) and after that your using DI exclusively anyway

Needed to adjust the Port Injector BRZ scalar down 3% to balance up the PI with DI.

Now getting pretty well 0 ltft (+/- 1%) except for the first couple near idle about 3% variation with large changes in intake air temps.

http://www.ft86club.com/forums/attac...1&d=1448249234I logged after changing PI/DI ratio.

http://www.datazap.me/u/yobiwan/sc11...zoom=4683-5433

CL AFR target become leaner. always shows 15~16

today I switched to original PI/DI table . and CL AFR is steady on 14.7


HKS V2 supercharger with 41.5mm restrictor
Tomei UEL header
Stock intake with KN filter
OFT tune.

Wow... that that is really strange. It should not have an effect on target AFR unless you changed the base fuel mapping. Something is really wrong.

I'm sure running this lean is not very good for your engine. Revert to your old rom until you figure out what it going on with this one.

If it's only just during cruising then I'd leave it, better fuel economy and all that. Your actual AFR doesn't quite go that lean anyway. I haven't seen that on mine though so I'm not sure why it's happening especially as in CL is should be targeting 14.7.

Is that actual AFR, or is it the requested AFR from the ECU? If it is requested AFR, mine is doing the same thing. If actual AFR is too rich, then the requested AFR goes lean to pull it back to where it needs to be. The actual AFR is what we need to concentrate on, Especially in Open Loop.

After running a slightly modified version of the port injection ratio table(0% in .20 loads) with 5% lower value on the port injector scalar, my fuel trims are still a bit high at the .30~.40 areas where its' running 70% port. Though this is on my new maf scale that was dialed to 68*f/20*c. I've decreased the value to -6% lower than the stock value and will see if that fuel trims will go down a bit more.

His low load cruising AFR's are averaging 15.6:1 and can go higher than 16.0:1 in spots, are you sure that's okay?
http://www.datazap.me/u/yobiwan/sc11...zoom=4991-5146

I finally found the Injector Scaling BRZ table, and decided to give your changes a try. I think you have the right idea. It is running rich in CL with increased PFI, so scale back the PFI Pressure to compensate. I'll give that, and your revised PFI to DI table a try today.

Yeah, quite a few engines run 15-16:1 in closed loop, Honda do to name one.

Just so you're aware, decreasing the injector scalar will make you run richer.

I agree with solidONE. Something is not right. mad_sb and others have tried to force lean cruise and not been able to. I wonder if your table defs or logging address for target AFR are right. What ECU Calibration ID are you running and where are you logging target AFR from; what is your stock ROM?

Would be interested to see your ROM and defs.

How right you are. I experienced the 1-2 punch of lower MPG AND less horsepower this morning. The less horsepower was particularly disappointing. :( I loaded a previous tune, and :happyanim: I'm back in business. :burnrubber:
So, making the AFR richer with Port Injector scaling will end up making Open Loop leaner, correct? Ideally I want a Closed loop AFR of 14.7, so that Open Loop will be just right.

A01E (S. Korea 6MT)
and logged from OFT

HKS sc
removed stock 2nd o2 sensor, using AEM UEGO wideband now.

and AEM wideband shows 15.6 AFR too.

but I changed back to stock PI/DI table and everything is fine now.

I'll send my roms & def to you.

Yes. We don't want corrections from CL applied in OL in this case. Assuming our MAF scale was done properly before we changed our di:pi ratio table.

I'm aware engines designed for lean burning, question is can this engine handle it specially since this engine has a history of burning DI seals. I suppose if he was running E85 then this would actually be closer to ideal and the engine wouldn't have as much trouble with possible problems associated with running this lean. Not so sure about doing this with petrol.

Lean burning at low loads I can't imagine being an issue, I doubt that the energy produced would be enough to cause any issues, especially as we're talking less than 10% off stoich.

Why 14.7 when stoich for e10 is 13.9? 14.7 is for e0 which isn't available anymore.

Sent from my HTC One_M8 using Tapatalk

Plenty of e0 up here.

I guess a boosted setup with the extra heat would be a good type of stress test of running leaner at low loads on petrol. If someone (ahem) wants to be the guinea pig, we may or may not have stumbled upon a method to achieve a lean burn. I surely wouldn't mind trying this out on my E85 rom. I'll volunteer myself for that once ztan or the rest of you programmer types work your magic. :D

E10 stoich?
 

A quick search with Google shows predominantly 14.13, rather than 13.9. Is that for WOT?

13.9 is what I use at work so was strange to see Toyota tune it to 14.7 which is lean if running on E10. Up here in MI the ethanol content can be higher than 10% at times

Target AFR 14.15%
 

Here in WA it's up to 10%. Especially in winter. My favorite station uses ethanol year-round though, so I'm changing my AFR table to 14.15 in the lowest sections, instead of 14.70. I also changed the BRZ port scalar 4.6%, since that was about how far it was off in CL. I know it gets the best mileage when it is just the tiniest bit lean in OL, so 14.15 should be a good target. This is the only table with AFR ratios I could find. It's an Open Loop table, but I think it is referenced for Closed Loop as well. See pic for more info. @thambu19, I only changed the 14.70 cells, or do you think I should re-scale the whole table 3.7% richer

for closed loop you need to alter the closed loop fueling offset tables they are the offset off 14.7 so if the table has -0.7 in it it means you will target 14, theier are two tables a and b alter both

In general running stoich or slightly rich will make the engine feel a lot better under load but ofcourse at the cost of Fuel economy

I've also noticed this in OL operation where the "commanded AFR" is actually a bit leaner than the actual requested values on the OL fuel map. This really messes with the MAF scaling tool as it tries to match the MAF scale to the "commanded AFR" and not the actual requested AFR on the fuel table.

@steve99, are these the tables to alter as well?

Yes they are the tables for closed loop, read the table properties in romraider, dont put 0 or positive values in as weird stuff happens and ecu ignors fuel trim compensations kind of open loop all the time.

@KoolBRZ they also don't seem to actually change the AFR you target in closed loop. Anything leaner than the minimum open loop enrichment value in the primary open loop fueling table is ignored and the closed loop fueling tables are referenced, however the ECU does seem to try and target stoich at all times.

Yeah, I thought maybe I could take the easy route and just change anything 14.7 in the definition to 14.13, but the calculations are more complex than that.

OK, this should do it
 

Here are my re-scaled Open Loop and Closed Loop tables that should bring my AFR down to 14.15. I just added .55 to all the cells in the A and B Compensation tables. I'll load up the tune and try it out this morning before I do my transmission fluid service/refresh, since I need it up to 42 C to measure correctly.

OK. Got the comp cells to all be negative values, and took it for a test drive again. Here is a log I took, http://datazap.me/u/koolbrz/1st-e10-...g=0&data=1-4-9 @thambu19, is there any way you could create a table of recommended AFR's by Engine Load and RPM's. I want to try getting my logs closer to stoich with the E10 I'm running now.

The ECU will show 14.7 at stoich for any fuel, so when it reads 14.7 you are at stoich for your fuel. The AFR reading is derived from the O2 sensor scale but the sensor works in lambda, lambda 1 is stoich and the sensor scale means that it shows 14.7. All you're doing is making it a percentage richer than that. I'm also not sure why you're doing what you're doing, all you're doing is reducing economy....

The real "workaround" for this would be to change your O2 scale, however the ECU will try and target 14.7 so you'll actually make it run leaner ;)

CL target afr=14.7 + value in closed loop table

there are probably some other compensations as well.

as you have put bigger negitive values in them the car is runnung richer in closed loop.

if you want to run close to 14.7 then put -0.01 in the cells in both the A and B tables.

As these tables are reverse engineered the ecu code often has multiple references to same table hence the need to change 2 identical tables.

As @Kodename47 said the ecu logic prevents targeting leaner than 14.7 and putting positive values in does not work, putting zero in appears to disable ltft in that area.

This appears to prove your point
 

Although I have no doubt you are correct, I sometimes doubt my understanding, so I thought a comparison would prove your point. I brought up the same tables in OFT OTS 91 Oct and E85 tunes. They are identical up to .5 load, then they branch off from there. Stoich is radically different for both fuels, yet they are identical. This proves your point, yet shows a different principle at work too. Above .5 and .6 load, there is a compensation applied that is unique to the fuel being used. The question now is, how to compensate for E10 above these loads to get the best economy and power.

Stoic ratio for petrol mixture is 14.7 parts air to 1 part fuel.
Stoic ratio for e85 mixture is 9.8 parts air to 1 part fuel.

The O2 sensor does not know how much air or fuel you started with. It only knows oxygen levels left in the spent charge. The O2 sensor reports in terms of lambda. If the lambda value is 1.0, the fuel is burned optimally, and started with the right mix. Whether you start with gas at 14.7:1 or e85 at 9.8:1, the lambda will be the same at the O2 sensor.

The ECU recalibrates the lamda value to read AFR for petrol that what you see in logs.

The fact that your running straight petrol or E85 does not matter to sensor and the ECU will try to still target stoic if you set the "afr" to 14.7.

The fuel trims will easily adjust for E10

All they really do in E85 tunes fueling wise is adjust the injector scaling so you don't run huge trims like 25%