EvolNinja

iTrader: (22)

I was reading How to Tune an Evo by nj1266 under scaling injectors. He have some numbers for the PTE 880cc which reads (batt voltage--ms) 7--2.186 9.4--1.325 11.7--0.833 14--0.534 16.4--0.351 18.6--0.231.

I'm still waiting for a new map after I sent Tamer the current log althoughI wanted to try to scale the injector myself because I want to drive my Evo after having it sit in the garage for almost 3 weeks.

Should I try nj1266's batt voltage/ms?

Currently my injector scaling is set to 713
Injector Battery Voltage
voltage ms
4.69 3.312
7.03 1.680
9.38 1.104
11.72 0.744
14.06 0.624
16.41 0.408
18.68 0.264

Under Mitsulogger:
Injector is set to 713
Latency @ 14.06v is set to 0.624
Latency @ 11.72v is st to 0.744

In my log of 10 min session, under Fuel Trim Low, I'm getting +12 all the way down.

Can someone help me so I can make the correct change to scale the injector? Thanks

fostytou

iTrader: (15)

I bet you can find all kinds of information on proper scalings and how to do it in here....

https://www.evolutionm.net/forums/ec...injectors.html

What other help do you need?

G20

iTrader: (13)

that's lean idle. Try bump up the latency values at 14v = .7xx and 11v = .8xx to see if it gets better. You may want to idle a little longer and also do some cruising for 15 mins.

I'm scaling my 780cc now and it's at -3 and +2 but I want to experiment more to see if I can get better number.

EvolNinja

iTrader: (22)

Need help for understanding the injector scaling log. The numbers I need to pay attention to FuelTrim_Low or O2 Feeback and WB AFR data? I notice that under FuelTrim_Low, the number pretty much stays 12 all the way down. But under O2 Feedback, it start with 0 then later it goes to as low as -8 and as high as +14. Also when logging during injector scaling, should I just log for at least 10 min or 16 minutes? I'm leaning toward the O2 Feedback as he data I need to focus on.

Oh, also a question about changing injector scale value. When I increase that value, do I need to increase or decrease the ms under the Injector Battery Voltage map? Thanks for the help guys

voidhawk

iTrader: (20)

I just did this myself for PTE780s, so here's how:

1. You need to change two things in your ECUFlash ROM: injector scaling (single number), and injector latencies (table). You'll need some starting guess, I used the numbers someone posted in a spreadsheet from the AEM wizard. But you could use my numbers for the 780s, they should be close.

2. You need to log Long Term Fuel Trim (LTFT) for "low" (=idle) and "mid" (=cruise). Don't use EvoScan to log, it has some issues with these. Use MitsuLogger instead which you can get for free from AktiveMatrix.com. After flashing the ROM, let the car idle for 15 min, then cruise for 15 min on the freeway.

3. Check what the LTFT's are after the 30 minutes are done (you only need the final values). Then do the following changes:

if low = mid & both > 0 then decrease injector scaling
If low = mid & both < 0 then increase injector scaling
If low > mid then increase latency
If low < mid then decrease latency

4. flash the new ROM and repeat until LTFT's are both close to zero.


I made myself a spreadsheet to help me scale things consistently (attached as a zip file, uncompress and you'll get an XL file). If you change the number on the blue box, it will scale the whole latency table up/down. For the injector scale, just keep tweaking the number you started with. Then I recorded the two numbers as "L-Scale" (latency) and "I-Scale" (injector) in the table on the right, together with the readouts from MitsuLogger. You can see it took me five iterations until I got everything right.

EvolNinja

iTrader: (22)

thanks voidhawk for the file. I was going to use the one made by AEM wizard too and work from there. I also saw your thread and was trying to find something to help me with my situation but I decided to get a thread going to get some insight quick. So where do I look for to get the LTFT data? Is it the Fuel Trim Low? I'm still confused as to what data I need to watch for. Thanks again for the help

DTM

iTrader: (4)

DO NOT use the AEM Latency's.
What Void posted is a great start for you. I would suggest Increasing the numbers a bit for your 880's proportionately.

DTM

iTrader: (4)

Also make sure you have checked for any air leaks (Boost as well)
TB seals will wreak havoc on your attempts at getting really close to 0.

EvolNinja

iTrader: (22)

My questions has not been answered yet. Please someone answer the question. What data should I be looking for? O2 feedback, Fuel Trim Low, wideband data etc Thanks

DTM

iTrader: (4)

Is this what you were asking to be answered? Because it has in numerous posts. But let me read the thread again.

DTM

iTrader: (4)

Do you have a Wideband configured to be logged thru EVOScan?
If so those values will help along with LTFT's (low, mid and high). Short term fuel trims will help you to initially dial in so that the "cross counts" from the O2 sensor will become closer or bunched in a pattern. But I found it easier to make sure you have accurate stock injector trims as a historical background. That way you can ideally set the values to be as close to the stock learning curve. Then you fine tune from there. Everyone does it differently.
You need to spend some time driving and logging. You can't expect someone to have a quick guide to scaling injectors. Its a learning process because everyone's standards and mods vary.

voidhawk

iTrader: (20)

in MitsuLogger LFTL low (idle) is called "Fuel Trim_Low" , and LFTL mid (cruise) is called "Fuel Trim_Middle"

EvolNinja

iTrader: (22)

Thanks. You answered my question. But after making some changes to the injector scaling and injector battery voltage, log for 16 minutes and under Fuel Trim_Low, it stays 12. No change. I look at O2 Feedback and it does show difference when I make the changes. I increase the scaling from 713 to 750. Injector battery voltage at 14.06 volt from 0.624 to 0.888 and 11.7v is changed from .744 to .914. Log some more data and see that under O2 Feedback, it jumped to +25. Prior to that it reads between -10 and +15.

Any suggestions?

voidhawk

iTrader: (20)

The fuel trim learning cycle of the ECU takes about 4 minutes, that's why it's best to let the car run for at least 12-15 minutes. This allows the ECU to learn what's going on, and then adjust the fuel trim about 3 times. This only happens if you let the car idle undisturbed for the whole 15 min, and then cruise it (without accelerating in between) for the whole 15 min. If you get on it, the ECU will operate in open-loop mode instead and this will turn off the fuel trim learning cycle.

If it stays at 12 and doesn't change, that means you are just too far off target and the ECU is compensating as much as it can (I think +/- 12 is the maximum it can go). You need to know both the "Fuel Trim Low" and the "Fuel Trim Mid" to figure out if you need to change the injector scaling or the latencies though, so you have to do both the idle and the cruise before deciding what you need to change next. It's kind of tedious ...

voidhawk

iTrader: (20)

one more thing: you don't want to change just one number in the latency table. If you make a change, the entire table should be scaled. I set up the spreadsheet to interpolate between the listed values for PTE680 and PTE1000 injectors. If you look at the plot "Latency" you can see that the curves are very close at low voltage, but further apart at high voltage. So if you want to make a change to latencies it's better to use the spreadsheet and change the blue box on Sheet1.