Ok im sure a few will have some interest in this, and some will already know (probably more than me). Please feel free to chime in if you have extra info.

Im making this thread to provide info on eprom tuning for nissan 240sx/D21 ka24e. This is basically same as uberdata/hondata tuning for honda ecus that most are familiar with. With nissan ecus, we use the program called Rom Editor available free from http://www.925style.com/. This is a very handy editor, that with the correct address file, allows us to easily tune our ecus like JWT or others. With the ka24e ecu (240sx Jecs, D21 Hitachi) we are dealing with a single 27c256 eprom that is currently located on the ecu board. All we need to do is change values on this chip (just like uberdata, except the eprom is already there). This obviously requires de-soldering the 28 pin eprom from the ecu pcb, which can be done a few different ways. Once it is removed, soldering a socket in place makes for easy changes.

I have the correct address files for both ka24e 240sx, and ka24e D21, as well as stock eprom files (or .bin) for both. This is all the files that you will need to begin tuning.

Before i go any further, here is some screen shots from my stock 1990 240sx 5spd ecu.

Fuel table

Fuel Map 3D

Ignition table

Ignition Map 3D

Global Settings

Now, this may appear candy-glossed, you should research heavily before you go trying your tunes. A wideband o2 sensor is highly recommended. I am by no means an expert with tuning these yet, I want everyone to know this info so we can get some info/file swapping goin on.

An eprom burner is required to make your own chips, i bought mine on ebay for about 70 bucks (willem enhanced eprom programmer). Anyone that knows a uberdata tuner, or is an uberdata tuner, you can use same equipment. The factory ecu's use a 27c256 UV-erase 28 pin eprom. These require a high intensity UV light to erase and are rather difficult to work with unless you have one. You can buy Flash replacement chips (erase with click of a button) , such as atmel at29c256 (most popular), or sf27c type.

You should keep your stock eprom chip intact so it can be swapped back in and/or copied.

27c256 are cheap eproms, you can buy them used at about $10 for 30, or even less. Atmel at29c256 are under $10 a piece new, these are what i use. Check out http://www.moates.net for sockets, chips, and even programmer/burners. I use the blue socket you see on that site, works nicely and has plenty of clearance on both hitachi and jecs ka24e ecus.

Ok i forgot anything else, maybe some questions would revive my memory. Anyone interested in the necessary files i have, i can email them to you.

BTW: Many older pc video cards used 27c256 UV eproms. You can re-use them if you have a high intensity UV light to erase.

click here for the Rom Editor software http://www.925style.com/old.html . Click "whats new" and you will have to register and log in, then your rollin.

Dude.. that's awesome, I was always curious to know how the chippng itself was done. I've done many honda ecus, but never really had a ka ecu to look at. How did you stumble accross all this information? Can this also be used to re-chip sr ecus? I'd like to get stock maps of sr ecus and maybe some tuned ones Just wanted to add that st chips can also be used, they are erasable with the click of a button. And I'm sure that if anyone needs any desodering, me or Devious will be happy to help out

BTW how did you obtain your adresse file, I can see the reading of the 27c256, but the address file somewhat puzzles me

TeckniX wrote:Dude.. that's awesome, I was always curious to know how the chippng itself was done. I've done many honda ecus, but never really had a ka ecu to look at. How did you stumble accross all this information? Can this also be used to re-chip sr ecus? I'd like to get stock maps of sr ecus and maybe some tuned ones Just wanted to add that st chips can also be used, they are erasable with the click of a button. And I'm sure that if anyone needs any desodering, me or Devious will be happy to help out

Check out ztechz.net, i gathered a lot of info from there, and just searching around on the net. I have a decent collection of some hard to find files, i would like to lend them to anyone interested.

Ok, actually, the 240sx ka24e and sr20det address files are somewhat interchangable (not really for full features, but the basics are there). So what most do when modifying the ka24e ecu is use an SR address file, or slightly modified one. I have an actual address specifically for ka24e 240sx. That was just an interesting bit of info i thought id add.

The SR and vg30de(tt) are fully compatible with this program with the correct address file. They are available from various locations including the place where you download program, and ztechz.net. You can also use consult type setups for real time tuning with sr and dohc ka (in beta stages but with working examples) i kinda talked about this in that intake thread.

You can also find all kinds of SR rom files, like MINES tunes and similar online. Check ztechz.net, There is even a tuned KA24E 240sx MT Tune up for dowload, 5hp on dyno!!.

Links of interest:http://forum.ztechz.nethttp://www.zcontrol.net/ (for SR/KA24DE consult)

It won't send me the login/pw... can you email me the software (rom editor and KA bin)?

sil80

hey, for the user name and pass, user "romeditor" pass "giveme". I wasnt going to say that at first unless someone had a registration error with that site. I will send you all the other files you need.

I can probably host the .bin and .adr files on my server if you want. And then all we have to do is put a link up , so everyone can download from my server and you don't have to always send them to whomever.

wut ya think? Plus it will be nicely organized.. so one can find it's way through it

Yeah that sounds great, ill send them to you. One problem though, i seem to have forgotten your email . You can just email me thru nico instead of posting here, ill get it that way. Ill also send all the D21/ka24e files for tuning the hitachi ecu as well.

I have much to post this topic, so anyone intrigued will want to stay tuned.

what hitachi ECU?

sil80

The 1990+ ka24e D21 (hardbody) ecu is Hitachi and has a different structure and layout. The 240sx uses a Jecs ecu.

Are they interchangeable with our ECUs? (if one made the 89-90 harness to fit)?Any gains/losses from such a swap?

sil80

The pinout and connector for both the truck/240 is the same. This makes for a possible interchange. I will look into this a bit further, as i know some differences will come up. Ill shoot some pics of the two ecus as well.

Ok now to what ive been waiting to tell everyone. Some may already know about this (very few im sure), but i have found a unit to "emulate" the stock eprom chip. This unit, combined with software that is designed for real time editing of nissan eproms, can turn a sohc ecu into a full real time standalone type unit. This cannot be compared to any type of piggyback type system, It gives you full access to the features of the oem ecu. And best of all, its cheap, much less than say an SAFC. Ok now for some more sohc eye candy

Live Edit ver. 2.2





This software can work all by itself without an emulator, to create a tuned .bin (just like romeditor). Overall i think it is a nicer program to use. You have the ability to easily expand the tables (more precise tuning at 6000rpm+), you can do this in romeditor but live edit just makes it easy. This program is available free for download http://www.engineers.auckland.ac.nz/~lmoo016/ .

Now, for the emulator. What this does is completely emulate an eprom (in our case, a 27c256). It has a 28pin eprom type connector that has a ribbon cable coming off, and that goes to the emulation unit. You then hook up your pc or laptop via serial and control with that (yeah you will pretty much need a laptop). The link for this unit (the best and easiest to use) http://xtronics.com/memory/pktROM.htm .

I have created a config file for live edit, for ka24e 240sx use. I will also set one up for d21 ka24e. The screenshots above are one of my personal ka24e tunes i had loaded up, and you will notice that all parameters all correct including all limiters. It even rescales for larger injectors, with a click of a button, very nice . The 2.2 version of live edit was updated only a few days ago, read on the link how to turn the demo version into 2.2 beta.

Ok just incase anyone is confused, and needs to know really what all you need to do this

Desoldered and socketed sohc ecu (socket costs about $6)Pocket Romulator (179.95)Live Edit ver. 2.2 (free!!)laptop or pc computer will all files installed

I probably have forgotten a few things in this post. Please ask any questions to clarify what is not understood.

you sonofagun.... everytime i think "wow this is it, this is what i need I am so set with these cool things for the KA..." you come out with some crazy stuff like this! i am drooling... give me a minute...

sil80

HAha.. yeah I had a nice long chat with DeviousKA.. and it was a nice eye opener. I can't wait to get my project s13 and start playing with it Of course head swap will be in, so the tuning will be key@!@!

hey i never looked into an ECU, but... the ROM chip im asuming it is. Is that in a slot or is it sauldered on the board? If it is saldered could you saulder a rom slot from like a 386/486 onto the ECU?

I am all nerded out seeing this..... lol

You cant use a motherboard processor socket, but its the same idea. Ill go pull my ecu, and post up a few pics. Check out http://moates.net/gmecm/hworder.html scroll all the way to the bottom and check out the S4 ZIF socket. This is the socket im using and it works very nicely. Then scroll back up a bit and you will see C1, this is the atmel at29c256 chip that works perfectly in our ecus, and is easy to erase. You can also buy a programmer to burn your own chips on that same page (Burn1, $85). I dont use that programmer, i found mine on ebay for about $70 (willem enhanced eprom programmer)

Picture quality isnt to great, I had to take pics with my palm pilot. They might be a bit large to but i wanted everyone to be able to see it.

240sx JECS ecu, with S4 socket installed (blue, on the right)

D21 Hardbody Hitachi ecu, with eprom desoldered and removed (bottom right)

Close up of socket (with standard 27c256 UV eprom installed). Unmodified, that eprom chip lays flat on the board. This is 240sx ecu.

Notice the difference in the Hitachi/Jecs ecu

whats the difference in the ECU? why does one have the rom chip and the only have the chip onboard

I meen is each of these out of a certain year. Like 90' ecu has it sauldered on and the 95' ecu has the rom chip plug.

I installed the program and can't do anything with it i keep getting memory set errors

Also the menu needs to be edited. It doesn't show everything unless you click everywhere.... kinda scary...

The difference is the layout and components of the ecu pcb. On that D21 hitachi ecu i posted a picture of, the eprom has be desoldered and removed (yes it should be there for operation, i was just comparing). The 89-90 sohc 240sx ecus are the same, the 90+ D21 ecus are the same (afaik, ive only checked up to '93). The 91+ 240sx ecus are completely different, they use a 16bit setup vs. 8bit of the sohc. Thats why when you see a chipped ka24de or sr20det ecu, they have a daughter board with 2 eproms. They use 2 8bits, more cost effective.

I dont know why you are getting memory set errors, i havent had any problems in that dept. And yes, in rom editor there is not enough room for all the menu buttons so you need to shuffle through to find what you need (it also does not show which one you are on). I know some have fixed this to show all of the menu, but im not sure how. I did not make either of these programs btw, there is plenty of support for rom editor, search around.

Try Live Edit, the latest version is nice and easy to use. You need to load a config file for the ecu, and then the rom image (.bin). I sent TecKniX all the files to host up on his site, probably be up shortly. In the mean time, in Live Edit, you can use the sr20det config file and the Sohc 240sx rom image.

oh lol i forgot to mention that my programs bar is missing since i installed this proggy. lmao.

I think you need a dos based OS. What OS are you using? XP acts funny with it

Your programs bar is gone? Very weird ive had none of those problems. Im using XP pro and i have installed it on a win2000 machine as well with no problems whatsover. Try Live Edit, send me your email thru the nico email (profile). Ill send you the proper files to get started.

Click on the Live Edit link i gave a couple posts above. Download the demo version and install. Then download the ver. 2.2 update on same site, and replace the demo exe with the 2.2 exe.

oh .... LOL mabie thats the problem im having i didn't updated it :P

Also man i think this is a windows 98 program i think thats why some of the buttons don't show i was looking at some of the screenshots.

Get on AIM.

Holy crap batman. v2.2 is totally different!!!

BTW man i didn't get the proggy in email. I checked. It was probobly to big just give a me a link

Alright I got all the files that deviousKA sent me up on my server, the address is: http://ka.slasher.org pretty simple hmm ?I'm thinking of also adding some pages that will actually link to the programms and also to some of the pics that deviousKA posted here.. you never know, might be helpful. If anyone wants to add something to all of this.. holla at me

ok I was bored for a few secs.. made a small img for the page .. let me know if you like it

Wow man, you hooked it up. It looks great, much easier to start tuning now.

thanks for the interest in the program guys :P

ciao - have fun

lawrence

Thanks deviousKA :P You did a lot of the work though..

link no worky