SophieSleeps

iTrader: (19)

So I deleted my LTFT's from a log file only. Simply because they were all 0.
I don't plan on not logging them.. But thanks for the tip.

As far as idle goes, I have it down so that my STFT's are roughly 1-2% and my LTFT are 0%.

I adjusted the first few cells as really a test to see what my next log would be.
I purposefully didn't adjust some of the higher Hz values because I didn't want them to affect my open loop tuning at WOT.

Unfortunately I can't install Mitsulogger...some stupid error.
I'll try again.

Thanks for all the help.

l2r99gst

iTrader: (2)

Great! It looks like you have it nailed down now.

Eric

SophieSleeps

iTrader: (19)

I am turning my car into a white deep throating monster.

C6C6CH3vo

iTrader: (9)

l2r99gst, your just the wizard I need to talk to. Is there any properly functioning reason why I have different FuelTrim_High values every log session.

Not every log, but every time the ignition is reset (key off) if I do a log the FuelTrim_High will be different, i.e., 113, 103, 97, 117, and so on.

Thanks

SophieSleeps

iTrader: (19)

Errr...so I'm using mitsulogger. Tried it today and I'm a little confused.

What units is
fueltrim high/low/middle in?
I'm getting values like -1 and 0

And 02FeedbackTrim is something like 4,5,6
Is this in %?

Mr. Evo IX

iTrader: (5)

This is great stuff! A little advanced for me but I think I understand what its for.


Question 1. Should my stock fueling be far off enough to be logging 114.0625 in both FuelTrim_Mid and FuelTrim_High with just a catback installed on the car? My idle stays put at 100. So.. In other words is it common for stock fueling to be that far off or do I have a mechanical issue that could be causing the fuel trims to be out of whack? eg dirty MAF, boost/vacuum leak, o2 issue, or another issue that I havent even considered?

Question 2. Does the ECU use values from the rear o2 to make fuel adjustments or only the front o2? If it did utilize values from the rear o2 wouldnt a mechanical o2 fix cause the ECU to think that the car is running lean and have it increase fuel trims to compensate?

l2r99gst

iTrader: (2)

If you just have a catback installed, then you wouldn't be using this table to fix your fuel trims. A catback will not alter the reading of airflow through the stock MAF.

Even on a stock car, fuel trims can be off. They are trims for a reason....so they can adjust up and down for a number of different reasons. You do want them to be as close to 0 as possible, but don't kill yourself trying to achieve something that isn't always possible.

I don't know what the 114 means in terms of percentage, so I don't know how far off that it. But, whatever you do, I would suggest not to use the maf scaling table to correct the trims. Your MAF shouldn't need to be calibrated since you didn't change anything from stock on the intake setup.

As far as I know, the rear O2 reading is just to check for cat efficiency. It should have nothing to do with fueling. The front O2 is for closed-loop fueling.


Eric

l2r99gst

iTrader: (2)

I'm not sure what 113 means in terms of percentage. Fuel trims should be scaled so that 0 is perfect, and then plus or minus a percentage from there. I don't know why EvoScan has them scaled the way they are.

Anyway, I think 100 is the 0 point, so I would say that you are fine. It's bouncing somewhat around 0, so I wouldn't worry about it.

Why would it vary from log to log? Well, if that truly is the LTFT-Hi, it should be used for closed-loop fueling at high airflow readings (I don't know the exact value). But, I would guess at very high RPM cruising, for example. Maybe you just hit that range every so often to make the trim change a bit. But like I said, I wouldn't worry about it. Your STFT will handle any abrupt changes in fueling necessary at that point.


Eric

C6C6CH3vo

iTrader: (9)

Thanks l2r99gst,

Helped me realize it's from closed loop activity either prior to, or at the beginning of the log episode before pressing "start".

OT
Iv'e been trying to pinpoint the cause of my AFRMAP deviation in respect to value on map and at least I now it can't be FTH

SophieSleeps

iTrader: (19)

How would you guys adjust this MAF scaling table based on my datalog?
I'm curious to see what you would do.

My g/s scale is above 40...so that means that my lookup table is slightly off.

keydiver

iTrader: (2)

If it is like the 1G, which it probably is, it is 1% extra fuel for each 4% TRIM. So, a TRIM of 114 indicates that the ECU is adding 3.5% more fuel.
The MAS Hz does tend to jump around a lot at idle. The MAS pulses are counted between each CAS pulse, so there may only be 2-3 Hz per CAS pulse, and then the pulse count you see on the logger is divided down quite a bit from a 16-bit number in the calculations, which makes it choppier :
mafraw16: 16 bit airflow sensor pulse frequency (mafraw16/10.24)Hz
mafraw16 = 8205*[airCnt0:airCnt1]/Tcas
mafraw: 8 bit airflow sensor pulse frequency (6.25*mafraw)Hz
mafraw: = mafraw16/64
So, just a difference of one little tick can throw the Hz count on the logger 6 Hz one way or the other at idle, where the count is extremely low already.
Jeff O.
aka keydiver

l2r99gst

iTrader: (2)

Jeff,

Thanks for the input.

What I meant regarding not knowing what the 114 meant was in reference to the many loggers that are available on this board now. Many of them have their trims and other loggable parameters scaled in different ways, depending on how the author or the user of the logger wanted to configure it. Most of the loggers have a configurable .xml file so that you can scale the logged ECU paramaters to whatever scale that you wish.

I am used to seeing the fuel trims of 0 being no correct, and negative and positive percentages from there, so that -5 means 5% of fueling being removed, so when I see people posting logs with different scaling or their own scalings, I don't want to guess what they are.


Off Topic: Jeff, thanks for you help on this matter of the scaling table. I was the one who emailed you a couple of times regarding this and posted on the DSM-ECU board. With your help, the DSM-ECU list and my own testing, it was pretty simple to nail down the workings of this table in the Evo ECU. The only thing that pretty much threw me in the beginning was that the table was only scaled to 1600Hz like the DSM tables.

For those of you who don't know, Jeff is one of the sources that I worked with in my research of this table and the person that I have mentioned numerous times in this thread and spreadsheet. He knows Mitsu ECUs very well and I'm pretty sure he and his team (or maybe just himself) have disassembled the entire 1G ECU and I even think the 2G ECU. I'm used to Tom Dorris and DSMLink for the 2G, so I'm not sure how much Jeff has invested in the 2G ECU.

Nonetheless, he is a great contributor to the community and very knowledgeable about the Mitsu ECUs. It's great to see him on this board.


Thanks,
Eric

SophieSleeps

iTrader: (19)

Excellent.

jcsbanks

That fits with what an OBD-II logger shows compared with Evoscan

fixem2

iTrader: (30)

Just to clarify, in EvoScan the STFT = O2FeedBackTrim and LTFT = FuelTrim_Med.

Also if the above colums are reading 113 and 117 then using the 1 for 4 formula above and 100 as Zero Point. We have STFT = 3.25% and LTFT = 4.25%.

Is this correct?