SophieSleeps

iTrader: (19)

So I have a few questions:

Is this applicable to an EVO IX ecu as well?

And say you re-scaled this so the MAF scaling shows up in hZ.
And you found out that you were 10% off from factory. Wouldn't it make sense to just add 10% across the board?

X + 0.10(X + 140) = new value


Can you dumb it down a bit?
I really don't do much ecuFlash other than tune my fuel maps and timing. I don't mess with the ecuFlash definitions or anything.

SophieSleeps

iTrader: (19)

My evoscan log at idle:


My OBDII scanner log at idle




I attempted to change the first value in the MAF table from 145 to 173:
And I can't make any sense of this because after scaling, my STFT is down to 0%.
HOWEVER, my wideband was reading up in the high 16 and low 17 AFR.
AND my STFT are up in the 17%
wtf mate? Did I go in the wrong direction? Should I have decreased by 10%?

I took 145 + 140 = 285.
285 * 10% (roughly my short term trim) = 28.5
145 + 28.5 = 173.5

SophieSleeps

iTrader: (19)

I just realized. It's saturday night.
I'm a handsome pimp and I am in my garage freezing me butt off while hot ladies are finding other dudes.
I must get out more.

Matthew333

iTrader: (29)

Is everyone trying to match #'s for gm (or other mas), or is anyone playing with speed density?? I cant tell the difference in the logs-

SophieSleeps

iTrader: (19)

If I'm not totally confused:

We're just trying to make MAF scaling work. Nothing to do with speed density.

Matthew333

iTrader: (29)

got it now- thanks.

l2r99gst

iTrader: (2)

Sophiesleeps,

Sorry, I was away for a couple of days and I am in a hurry to go watch the superbowl today (Go Bears).

Anyway, your logic is correct and you did the right thing.

It looks as if changing that table reset your LTFT to 0 or possibly in the second log your car wasn't warmed up yet?

Anyway, to see how much your fueling is off, you can basically add your LTFT and STFT. In your first log, you had your LTFT maxed at 12.5%. And your STFT was around 10-12 %. So, the ECU was basically adding up to 25% more fuel.

In the second log, after your change, your LTFT was 0 and your STFT was +17%. So, the ECU was now adding only 17% fuel. I'm curious as to why your LTFT was 0, though. Either you reset your ECU (unplugged the battery), or simply flashing or changing that table reset the LTFTs. Let it idle for a good 10-15 minutes and the STFT will push itself over to the LTFT. Post back with the numbers when the STFT is around 0.

If your second log is good, it look like you still may need more adjustment, though, because your LTFT only has 12.5% of room to adjust and it looks like you are still adjusting about 17%.

Also, for idle, I would probably change the first two values in the maf scaling table.



Eric

SophieSleeps

iTrader: (19)

I'm going to change them again tonight to see what happens.
I did not reset the ECU.
And the car was warm when both readings were taken.

Thanks for the help.
Go bears.

SophieSleeps

iTrader: (19)

How are you logging STFT and LTFT?
I'm finding that my logging is fairly "jumpy" and it's hard to get a great idea of where my STFT's are for a given airflow?

Also, do you have an idea of what airflow is cruise, (i know idle is between 19-25), just trying to get an idea of what Hz is associated with what type of driving.

MalibuJack

iTrader: (5)

STFT's are always going to swing back and forth as their responding to the O2 sensor's input..

SophieSleeps

iTrader: (19)

Yeah, I realize that.
So how do you get an accurate datalog?

Also, are you able to log STFT and LTFT in evoscan? If so, what units are they in?
I'd rather just use one program to log instead of bringing my OBDII scanner with me everywhere.

Here are the columns I see but can't really make out what they're for:
FuelTrim_Low
FuelTrim_Mid
FuelTrim_High
O2FeedbackTrim
O2Sensor
O2Sensor2

SophieSleeps

iTrader: (19)

For example: What would you make of my datalog this morning?
I adjusted some stuff last night and increased MAF scaling by about 20% for the first 6 or 7 cells. My LTFT's were 0 so I deleted that column to make it easier to read.

MalibuJack

iTrader: (5)

Mitsulogger and Evoscan can both log fuel trims..

Mitsulogger's values mirror what an OBD-II value would be.. In Evoscan 100 is the same as 0, so less than 100 would be negative, more than 100 would be positive..

In any case.. O2FeedbackTrim is the STFT and Fueltrim_Low, Fueltrim_Med, Fueltrim_High are the long term fuel trims..

Low is Idle, Medium is Cruise, and I think High is for high load closed loop such as when the A/C is on, but I've never actually seen High change on my car..

SophieSleeps

iTrader: (19)

So if I log 02feedbacktrim in evoscan I can't really pinpoint what the MAF value is...

Say I see a 130 value.
That isn't in lb/min, lb/hour etc. So I really wouldn't know anything except that it's adding fuel or pulling fuel.

Is that correct?

l2r99gst

iTrader: (2)

Just log your STFT and LTFT with whatever tool you want. I see that Jack explained what the values were in Evoscan. If you are using a MUT logger, then log your Hz, too, so there is no guesswork for which cell in the maf table you need to alter.

As far as stft jumping around, that's normal. But, as long as your LTFT isn't maxed out, then the STFT should eventually be pushed over into the LTFT and the STFT should jump around 0.

I saw in one of the posts above that you said that you deleted the LTFT since it was 0. I think it may have just been reset to 0 somehow, either from the flash or battery reset, etc. You absolutely must still log LTFT. It will not remain 0. The STFT will be pushed over into LTFT after a while.

Also, in one of your post above I see that you stated that you altered the first 6-7 cells in the maf table. I would take things one step at a time. Get idle dialed in first. That should be the first one or two cells. Then, if you have bad trims at cruise still, then see what Hz you are cruising at and then modify 1 or two cells in that area.

You have to remember that altering these cells will be altering your closed and open loop fueling. So, don't just start making changes to cells that may not need them. The higher cells shouldn't really need to be touched since most likely you will be open loop at that point and you can simply use your open loop fueling tables for adjustments. It's the lower Hz closed loop fueling which we get to alter with this table to bring our trims back in check when a certain modification alters the airflow reading of the MAF.


Eric