Why the ecu make my tune run richer over time ?

[Kodename47]

Originally Posted by FA20Club.com

yeah but you change fuels too and that takes time to adjust since youre using map switching the trims dont reset like if you flashed in a new file when you change fuel. that has to be considered as well. thats why i told you to run through more than a tank after switching before logging.

Can you clarify that? I thought the trims were stored per map? Or are you suggesting that just switching maps doesn't clear trims?

[regal]

Originally Posted by s2d4

How did you arrive at this conclusion?
You were referencing the wrong sensor?
I am beginning to think you are just as special as regal...

Any ADC chip on an ECU has a finite bandwidth, increase the range on the O2 sensor you lose resolution not a big deal and probably well worth if if going forced induction..

Also requesting the tuner to target a less aggressive tune to reduce knock and the trims (corrections) will stray less. Mad_SB's strategies are what us old special guys call a "track tune", you may have a bit less Hp on the dyno but the tune will be more consistent day to day tank to tank.

[R3d]

just do like elvis graton and write bilingual one shot pis ta pas a traduire XD

[NoFear99]

The only way to fix this issue is to continue to send logs to your tuner once a week or every two weeks to show him how your tune react over time and this way tuners should be able to stabilize the afr.

Well this is what I understand after several exchange with Tony in pm.

[Toyota John]

Originally Posted by mad_sb

I know lol



The way I would handle it:
1. Turn off the long term trims by zeroing out the Closed loop AFR A&B tables
2. Set all the Transition timers to zero
3. Set the Min Openloop AFR to 14.5
4. Adjust the Fuel map so AFR target is richer than 14.5 anywhere you want to be openloop
5. Log LOTS of miles with varied driving conditions, wot, cruise, roll-ins at various rpms etc etc
6. Poor over the log data to decide if you need to rescale the maf, tweak some of the comp tables, tweak injector scaling, etc etc

Generally, Once the long term trims are turned off and the timers are zeroed out, it only takes a couple of tweaks to get the short term trims down to +/- 10%. At that point you can experiment with turning the long term trims back on. I always prefer to leave the timers at zero so the transition from closed to open loop is based on engine load, rpm, and desired AFR.

You should start by keeping an eye on things for a couple days while you are logging and see how the long term trims move around. Then you will need to talk with Toni to decide how to handle it. If the long term trims were staying around + / - 5% i would not worry much and just adjust the tune... but +/- 10% is a little much to tune around.

Also, i should mention there are multiple long term trims. The ECU uses bins based on the maf g/s reading. There are 4 bins i believe, idle, low medium and high load. I don't know the exact g/s ranges (that table has not been defined yet). That is why if you go WOT from low rpm, you will see the long term trim change. This also allows you to be clever about the transition points... you can set your fuel map up so that it transitions to openloop at say .8 load at lower rpm and possibly avoid setting the high trim but still keep the afr where you want it... open loop does not have to mean rich afr.

Mad_SB I am confused when you say "zeroing out the Closed loop AFR A&B tables" Do you mean putting a zero in the Closed loop tables or 14.7? I read your older post about limiting the fuel trims but I thought you said to change the Closed loop tables to 14.7? I am using ECUTEK so some might be a little different but it should be almost the same.

Also the names of the other tables seem to be a little different. Should I zero all of these too?
Closed Loop Delay Maximum Engine Load
Closed to open loop Delay periods
Delay close loop engine load Timer
Delay open loop fuel load Threshold #1
Delay open loop fuel throt thresh #1

[Kodename47]

Originally Posted by Toyota John

Mad_SB I am confused when you say "zeroing out the Closed loop AFR A&B tables" Do you mean putting a zero in the Closed loop tables or 14.7? I read your older post about limiting the fuel trims but I thought you said to change the Closed loop tables to 14.7? I am using ECUTEK so some might be a little different but it should be almost the same.

Also the names of the other tables seem to be a little different. Should I zero all of these too?
Closed Loop Delay Maximum Engine Load
Closed to open loop Delay periods
Delay close loop engine load Timer
Delay open loop fuel load Threshold #1
Delay open loop fuel throt thresh #1

If you zero the timers, then the rest don't matter AFAIK. So just:
-Closed to open loop Delay periods
-Delay close loop engine load Timer

As for the CL AFR tables, he means fill them with 14.7

I can't see a min CL AFR table in ECUtek though, so I assume that the stock value of 14.0 is used.

[Toyota John]

So what you saying is if i zero the two tables you listed, then the rest of the tables i list have no effect, if they are zero or stock values?

[Kodename47]

Originally Posted by Toyota John

So what you saying is if i zero the two tables you listed, then the rest of the tables i list have no effect, if they are zero or stock values?

Yes. Read this:
http://www.romraider.com/forum/viewt...c8b44bc64d2efd

[wparsons]

Anyone thinking they have this "issue" should log the commanded AFR, actual AFR and both ST and LT trims.

What is probably happening (without seeing full scope of data) is that the actual AFR is leaner than the commanded AFR but eventually after enough driving the LTFT catches up and the two AFR's are closer (or the same). This isn't an issue with the tune or the car, but a scaling issue with the MAF (or possibly injectors if they've been swapped and not scaled properly).

With a properly scaled MAF the trims should be much smaller, or zero even after weeks/months of driving.