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ECUflash How to: Get a basic tune with ECUFlash

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The guide is to show a DSM owner how to get a basic, driveable tune using ECUFlash. Following this guide in no way makes the users car "raceready". This guide is only to show a person how to get a useable tune for their 98/99 DSM. Further tuning may or may not be necessary. The user take all responsibility in any damage done to the vehicle and is following this guide at his or her own discretion. In writing this guide, I am assuming that the user is computer literate.

Table of Contents:

1. Introduction
2. Must Do's Before Tuning
3. What You Will Need
4. Quick Recap on Widebands
5. Installing Ceddymods
6. Retrieving Your Car's Stock Tune
7. Initial Tuning
8. WOT Tuning
9. Idle Tuning
10. Cruise Tuning
11. Wrap Up

1. Introduction:

Hello fellow DSMer, I am Dan, owner of a 99 eclipse gsx. I have been playing around with this engine and tuning software for about two years now figuring everything out about the car. I don't know everything yet, but I am getting there. This guide will help you to get a basic tune to drive your car to compensate for larger injectors. Also, this guide would not be possible without the great research done by Ceddy. Please support Ceddy and his hard work by donating $5 dollars when you download his amazing software.

2. Must Do's Before Tuning

I cannot stress this enough. These following checks MUST be made before you install your upgraded injectors. If you do not have ALL the items on this list complete, tuning will be EXTREMELY difficult and EXTREMELY dangerous to your car's engine.

Wideband sensor: You will need a wideband to log Air/Fuel ratio. The recommended position for this is to be welded in your downpipe before the flex section, this will give you the best readings. If you do not have a wideband installed, there is no point in continuing, a narrowband is just not good enough.

Exhaust leaks: Make sure you have all exhaust leaks fixed as any exhaust leaking out can cause fluctuation in your wideband readings. Also, pre-turbo exhaust leaks can cause a hell of a problem with spool times.

Logger: You will need a logger to help you tune. It is a necessity. Since you are using ECUFlash on your laptop already, I would suggest Evoscan, as it uses the same hardware and is only $25. It is available in the What You Will Need section.

Upgraded fuel pump: There is no point in upgrading your injectors if you still have the stock fuel pump. Get a walbro 190 or 255 before you begin.

Fuel Pressure Regulator: Some people will argue that the stock FPR will work fine. I would rather be able to have an FPR that will show me my pressure. This will allow you to KNOW that you are at the right pressure and it will not be overrun.

Recommendations: I would also recommend that once you have your wideband installed, to drive around with it (on your stock injectors)for a week to get an idea of what a healthy tune looks like A/F wise. This will give you a better sense if you tune is off when tuning.

3. What You Will Need

You will need the following to tune with ECUFlash:

ECUFlash itself. Available at this link --->

(NOTE:)If you are using Vista/Windows 7. Ceddy recommends to NOT put them in the default path, make a new folder OUTSIDE of programfiles.

Ceddymods. Available at this link ---> (You don't need BigMaps or SD, just get the basic Ceddymods.

(Optional) Evoscan. Available at this link ---> Mitsubishi/Subaru/OBDII/CAN EvoScan Software

Tactrix OpenPort 2.0. Available at evoscan website or tactrix website.

Mitsubishi Reflash Connector. Again, Available at evoscan website or tactrix website.

4. Quick Recap Widebands

The wideband is a ratio of Air to Fuel. For example, 14.7:1 is 14.7 parts air to 1 part fuel. 14.7:1 is the best ratio for emissions control and that is why the engine always shoots for it. Your wideband will not show the 1, it will just show 14.7.

When you are at idle or cruise, your wideband should be reading anywhere from 14.5-15.4 on a healthy tune. It should be cycling from below 14.7 to above 14.7 constantly. This is what it is supposed to do.

When you are driving and you let off the gas the wideband will read above 18:1, or it will read --. This is what it is supposed to do. You are not adding any fuel so it is just picking up oxygen. The range of most widebands is 10 to 17.9.

5. Installing Ceddymods

When you download Ceddymods from his website it comes with the following files that you will need(there are other files but you won't need them):


You will need to put them in your ECUFlash directory. So, go to your ecuflash directory, which (if you let it install to the default path)should be under ProgramFiles>OpenECU>ECUFlash and put them in the following folder rommetadata>mitsubishi>eclipse>

Also, you will need to install the ROM and XML files for your vehicle. Go to the following link and download both the ROM and XML files for your year. Then also put them in the same folder as the last files.

Here is the link to the ROM and XML files --->

That's it. Ceddymods is installed.

6. Retrieving Your Car's Stock Tune

After you have ECUFlash, with Ceddymods installed, your openport cable, and your reflash connector, you are ready to retrieve your stock tune and learn all the features of ECUFlash and Ceddymods.

Under your dash, near the center console you will find your OBDII port and just behind it is another port. The reflash connector will plug in to the port in the back, and the openport will plug in to your OBDII port. (NOTE: The reflash connector connects to the openport as well through a cable). You should see the lights come on on the openport. Then plug the openport in to your laptop.

On ECUFlash you should see three icons at the top that have arrows. The first is to retrieve a tune, the second to flash a tune on to your ecu, and the third to test-write ecu. You want to choose the first option. ECUFlash will start going to work and a progress bar will show itself on the bottom. After 30 seconds or so it will finish. (openport cables can be funky, if it is not making a connection jiggle the openport at the OBDII connection until it works)

When it is complete you will see a new world open up for you. If installed properly you should have a ton of features available to you on the left side of ECUFlash (Fuel, Timing, ETC). If all you see is "Rom Data" then the files from Ceddymods are not in the right location.

You now have your car's stock tune. Save it somewhere on your computer in case you need to go back to stock someday. Use a name you will easily identify, mine is "stock tune".

7. Initial Tuning

Finally, the fun begins!

At this point, go install your new injectors.
Next, you will need an initial tune for the injectors, so here is what you need to do.

All injectors have a flow rate and a latency. You will need to find what yours are, either from the website of the manufacturer or from the following list I have borrowed from Ceddy's website:

Injector Brand ---------- Flow ------------------ mSec

1G/2G ------------------- 450 ------------------- 0

Clinic 750 -------------- 750 ------------------ .330
Clinic 850 -------------- 850 ------------------ .330
Clinic 950 -------------- 950 ------------------ .330

Delphi 680 -------------- 680 ------------------ .210

Denso 660 --------------- 660 ------------------ .180
Denso 720 --------------- 720 ------------------ .405 - .450

FIC 650 ----------------- 650 ------------------ .210
FIC 750 ----------------- 750 ------------------ .315 - .330
FIC 850 ----------------- 850 ------------------ .315 - .330
FIC 950 ----------------- 950 ------------------ .315 - .330

Hahn RC 625 ------------- 530 ------------------ .180

ND 560(Evo8) ---------- 560 - 575-------------- -.048
ND 660 ------------------ 660 ------------------ .180

PTE 580 ----------------- 535 ------------------ .180
PTE 680 ----------------- 640 ------------------ .288 - .300
PTE 780 ----------------- 748 ------------------ .300 - .315
PTE 880 ----------------- 840 ------------------ .420
PTE 1000 ---------------- 940 ------------------ ???

RC 550 ------------------ 550 ------------------ .180

After you have found your flow rate and latency you will need to put them in to your tune so your ECU can make the necessary adjustments to how it adds fuel.
So, with that said, open up "injector scaling". This is the flow rate of your injectors. So, click the current 450 and then press = and put in your flow rate.
(NOTE: The number you put in may be different than what it shows, for example, I put in 660 for my injectors but it shows 661, this is ok)

Next are the latencies, open up "injector battery voltage latency compensation"
Now, within the latency menu, press "edit" then "select all", then press "edit" again and "add to data", then put in your latency. This will adjust all of the numbers by the entered amount.

Next, save your file with a name you will easily identify (Mine is 660cc Tune) Then write it to your ECU. (IMPORTANT: Make sure your laptop has good battery whenever you write the ECU) This will take a minute the first time you do it. After that you have a base line tune, so start your car! (and check for injector gas leaks!)

Do not worry about the A/F reading or how your car sounds for the first 30 seconds or so after you start it. It will be all over the place, most likely. After 2-3 minutes of idling, the car should have settled down. At this point you need to look at your A/F readings to make sure everything is within "working" range, not "optimal" range. You do not want anything over 17:1 A/R or under 12:1. If you are over or under those limits you will need to try different settings for your injectors. If you are too rich you need to raise your injector scaling, if you are too lean you need to lower your injector scaling.You SHOULD be between 14:1 and 16:1 on your A/F when all is said and done. If this is correct then you are ready to tune for WOT.

8. WOT Tuning

Ok, at this point your DSM should be idling a little funny, this is fine.
Before we tune the idle, we want to tune WOT to get the right injector scaling dialed in.

First off, when you are ready to tune for WOT open your tune in ECUFlash. Open "High Octane Fuel Map 1". These are the AFR's the ECU is shooting for under different RPM's and Load. What we want to do here is make all the numbers in the last 4 columns the same. So, click and drag and select all of them at once then press =.I suggest using 10.5 because it's not too rich or too lean. After adjusting those, save the tune and flash it to your ECU. Start the car and let it idle a few minutes. You will notice every few minutes of idle the car sort of stumbles and then recovers, don't worry, we will get to that later. For now, let's take the car out!

So, what we are trying to do here is match the readings on the wideband to the 10.5 we put in ECUFlash. Do some WOT pulls in 2nd gear and watch your AFR. You should be around 10.5, if you are too rich (10.3 or lower constantly) you will need to raise your injector scaling. If you are too lean (10.7 or higher constantly) you will need to lower your injector scaling. After a few tries you should be pretty close to your 10.5 throughout the pull. Congrats, you're done WOT tuning.

IMPORTANT: If you notice you are much leaner than 11 STOP and go lower your injector scaling, running too lean can damage your motor. Also, most widebands will only read as low as 10, if your AFR is lower than 10 then your wideband will still only show 10.

IMPORTANT 2: While doing your pulls you should be logging them. Log for knock sum. Too much knock is bad. I occasionally get 2 knock on hot days. Anything over 7 is really bad and you'll need to either adjust your settings or richen your fuel mixture. We are NOT shooting for 14.7 during WOT. We are shooting for 10.5

9. Idle Tuning
Ok, now that we have WOT dialed in, it's time for idle tuning. Here we need the logger. The following items NEED to be logged. Fuel Trim Low (LTFT), Oxygen Sensor Feedback Trim (STFT), and Oxygen Sensor. First let's clear our fuel trims. unplug the battery and turn the lights on, let all the power drain out so the fuel trims in the ECU reset. After 30 seconds or so, plug the battery back in. Start the car and log. Every 4 minutes you will see Fuel Trim Low change. Fuel Trim Low is the ECU adding or subtracting fuel shown in a percentage. What we want here is + or - 5%. So, let the car idle and check it every 5 minutes to see where you are at. Generally it will either keep going up every 4 minutes, or keep going down. After you let it idle for 8-12 minutes see where your LTFT sits. If it is ABOVE +5% then you need to raise your injector latency, if it BELOW -5% then you need to lower your injector latency. To complete idle tuning, let it idle for 16 minutes. If after those 16 minutes it is still within 5%, then you are done. Anything within that 5% is acceptable. Every time you change the latency you need to reset your fuel trims, so unplug the battery again ETC. After you are done with idle tuning, then you only have cruise tuning left and you are done.

NOTE: Your oxygen sensor should be moving all over the place from 0.1 to 0.9. If it is not moving than you either have a bad o2 or your initial settings are incorrect. Also, your STFT can give you a decent estimate if your latency is too high or too low. It reads the same as fuel trim low but it constantly changes.

Cruise tuning in the works...
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