Electrical DIY Megasquirt II V 3.0 stand alone ECU build.

CarMichael Angelo

my rearend will smell so minty fresh,
15 Year Member
Nov 29, 1999
10,641
9,253
234
Birmingham, al
Well here I go again. In keeping w/ my "backwards build" theme, I'm starting the build on the ECU for the future Fairmont.

Unlike my last project, which was an exercise in how primitive I could build a car, this car will be the opposite of that. Where as last years car was carbureted, this one will have digital, laptop programmable, F.I.. Where in the last car was naturally aspirated, this car will be force fed. Given the the engine is exactly half the size of last years car, it will almost have twice the power. To accomplish that, it's gonna have to be forced to breath the air at about 2 times the atmospheric pressure we breathe.....aka AROUND 30 psi of boost. It will be fueled on E85 and will not be intercooled so...........:banana:

To insure I don't blow up junk, I chose a complete stand alone kit, as I intend to replace the entire engine harness on this car. I will replace the entire electrical system for that matter.

You do not have to do it that way however, Megasquirt makes kits that will directly replace the EEC IV so that you can retain your engine harness, but I'm all about hiding that crap, so I'll start w/ a new custom harness to that end.

I chose the MSII kit w/ the 3.0 motherboard. I will let me provide for controll of fuel, spark, distributor less ignition, boost control, and it features an internal 4 bar map sensor (optional).
There is a even better step up MB, (v3.57) but for my purpose had some extra stuff that I didn't need.

Introductions aside,...it seems I have forgot that I have to get ready for dinner, so I'm gonna have to continue this the next time I sit down...pics to follow.
 
  • Sponsors (?)


Back for a minute:

So for 400.00 all this stuff comes in a box 12" x 6".

You get:
mustangbuild032.jpg


Plastic bags w/ diodes, resistors, capacitors the aluminum case, and the connectors for the future engine harness.

mustangbuild031.jpg


They call this thing a "stimulator" another DIY kit so you can test your completed ECU. (It's a kit you build to test the kit you built):confused:

mustangbuild033.jpg


Boost controller. (don't ask me how it works, I don't know yet.)

mustangbuild034.jpg


4 bar map sensor w/ barometric correction for altitude,...( just what I'll need for my attempts on the race to the top of Pikes' Peak);)

mustangbuild035.jpg


Tools, to include eyesight enhancement ( some of that junk is very close together)

Unfortunately, that's all there is for tonight,...my soldering iron is too big for the tiny circuit work, and I'm all out of low melt solder,....so .........................to be continued:
 

Attachments

  • mustangbuild032.jpg
    mustangbuild032.jpg
    7 KB · Views: 293
  • mustangbuild031.jpg
    mustangbuild031.jpg
    7 KB · Views: 303
  • mustangbuild033.jpg
    mustangbuild033.jpg
    7 KB · Views: 310
  • mustangbuild034.jpg
    mustangbuild034.jpg
    7 KB · Views: 271
  • mustangbuild035.jpg
    mustangbuild035.jpg
    7 KB · Views: 285
Good luck, looks like a lot of work. Probably why I just got the fast xfi2.0 I'm just not that ambitious I can't wait to see how it all turns out!
 
Now you can go out and buy a micro-min solder set-up. Always wanted to play with the Megasquirt, but lucked into an AEM system. So, no IC? Cooler charge temperatures are always good. I believe all of the 2.3 factory systems had them and am pretty sure most of the guys upgrading the XR4TIs and SVOs are using front mounts? Really was just hoping to learn from your tendency to hide stuff. I was hopinh you would come up with something trick.
 
Good luck, looks like a lot of work. Probably why I just got the fast xfi2.0 I'm just not that ambitious I can't wait to see how it all turns out!
It is alot of work, and the small parts are daunting. But once you try it, it isn't all that hard. the key is to have a good precision soldering iron, plenty of light, and the mega-magnifiers to see what the hell you're doing.

Now you can go out and buy a micro-min solder set-up. Always wanted to play with the Megasquirt, but lucked into an AEM system. So, no IC? Cooler charge temperatures are always good. I believe all of the 2.3 factory systems had them and am pretty sure most of the guys upgrading the XR4TIs and SVOs are using front mounts? Really was just hoping to learn from your tendency to hide stuff. I was hopinh you would come up with something trick.

I do have a Chinee A to A I/C. may as well run it since I have it, but the E 85 should produce it's own reasonably cooled aircharge just as a byproduct of using it ( I think)

I wish I lived close...I'd like to get my feet wet in some 2.3L EFI fun. I have two projects behind the one I'm working on and one is a 2.3L Turbo.

It wouldn't matter if you lived next door, this thing ain't gonna run for the next year at least.:nonono:

Good stuff. It could theoretically control a meth injection system too, right?


It should, I'll only be 15% shy of doing just that.
 
3 times our atmosphere? thats 44.1psi.

anyways meth is always a good idea when running that much boost. also a A/A IC is great but why not a liquid to air also the e85 will run a little cooler then pump gas or race gas but wont be as cool as your thinking.
 
3 times our atmosphere? thats 44.1psi.

anyways meth is always a good idea when running that much boost. also a A/A IC is great but why not a liquid to air also the e85 will run a little cooler then pump gas or race gas but wont be as cool as your thinking.

Yeah,...thanks for the math correction Pep,....got to thinking about it after I said it but was at work and couldn't change it, and forgot I said it. (until now). You shoulda quoted it, my momentary inability to add 14.7 would have been set in stone.

I'm gonna use the A2A because that's what I got. I was planning a couple of dedicated 10" radiator fans for it to force air through the core, ( Hmmm kind of like turbocharging the intercooler),......What tha:doh: Wait a minute!......now I'll probably have to come up w/ a way to intercool the fans cooling the intercooler.
DAMMIT!:fuss:

Maybe in the long run it'll be OK.
 
Yeah,...thanks for the math correction Pep,....got to thinking about it after I said it but was at work and couldn't change it, and forgot I said it. (until now). You shoulda quoted it, my momentary inability to add 14.7 would have been set in stone.

I'm gonna use the A2A because that's what I got. I was planning a couple of dedicated 10" radiator fans for it to force air through the core, ( Hmmm kind of like turbocharging the intercooler),......What tha:doh: Wait a minute!......now I'll probably have to come up w/ a way to intercool the fans cooling the intercooler.
DAMMIT!:fuss:

Maybe in the long run it'll be OK.

I've always thought A2A as the way to go on a street setup. Consider this before applying a lot of fans to the intercooler... Your by pass will be open when you're sitting in traffic or at a stop. When the A2A is actually doing it's job (by-pass closed), you're going to be in motion. Fans at that point would only be a restriction to the cooling surfaces. I might be more concerned with ensuring air has nowhere to go but through the heat exchanger when I'm moving.
 
Wow! if it's gonna take me this long to build this car, it'll take years.:nonono:
Between the main board build, and the "stimulator" intended to check functionality of the main board, I have 4 hours into it so far. While that isn't that much of a big deal,...the fact that it has taken me 40+ hours to find even that time to sit down long enough to do it is what I'm talkin' about.

Oh well,.....such is the plight of the working man w/ house, wife, and kid. ( Now w/ 55 hour a week job):rolleyes:

Starting w/ a newly purchased 15 watt soldering iron, 60/40 rosin core solder, and the Megasquirt Mega manual running on my computer, I started w/ this blank main board:

mustangbuild040.jpg


Then following the assembly instructions for the main board, you just start soldering the components on the board. The board is laid out w/ numbered, silkscreened spots to solder each respective capacitor, resistor, diode, and various other little doo dads w/individual bags of each matching numbered capacitors, resistors, diodes and various other little doo dads that correspond accordingly. Just like painting by numbers.

mustangbuild042.jpg


So for instance there are 10 of these capacitors that are supposed to go in each respective area marked w/ C-1,3,13 and so on. Easy Peasy right?

The MM instructions are very clear, and should be read completely before you solder a single thing though, as there are several decisions that have to be made along the way that they cannot tell you what yo do,....i.e. whether or not you want to enable a stepper motor Idle Air Control circuit, or whether, and what type of ignition control you want to provide for.

The MSII will work w/ Ford's TFI system, as well as Fords DIS system, and since I wanted to go distributorless w/ this combo, I needed to decide which way I wanted to go in advance, and I had to make certain circuit modifications via the usage of "jumpers" that link parts of the board to allow for it. So bottom line, read it completely before you begin.

The instructions also caution you to not make the main board your first project if you have never soldered a circuit board before, and direct you to a couple of "test" projects that you can probably buy from Radio shack. I had done a couple of these before, so I wasn't worried about that, but it is tedious,....you will need a Magnifying Glass on a stand to make soldering that much easier. Just my .02 worth,..but if you think you got eagle eyes,........you go bird boy.

So you plod along for about two hours after you start soldering away like there's no tommorrow, the instructions will stop you to ask for modification decisions, and provide for the opportunity to check the operation of the circuits you just soldered. Before I built the main board I chose to build that "tester" first, MS calls it a stimulator,...and it had to be completely assembled. Suffice it to say,..this thing started as a blank circuit board as well:

mustangbuild038.jpg



The two leads are for a 9v battery connection, it will run either off of that, or a wall wort that you buy when you buy this kit. W/ it you can simulate all aspects of a running engine to the MSII to be sure the work you are doing will run that engine when you plug the damn thing in. I highly recommend you spend the extra money for this kit.

It took me two hours to build that thing, and I started on the main board the next time I had a chance,...I managed to make it far enough to get to the first check point to test the power circuits and to decide on my ignition of choice:

mustangbuild041.jpg


mustangbuild037.jpg

What you are seeing is the board w/ the DB 37, and DB 15 connectors as well as the first few caps, diodes doo dads, the socket for the processor, the heat sink and a MOV installed. The close up shows why you really should use a magnifying glass.;)
I should be able to plug in my serial cable from my computer on the one end, a DB37 cable from the stim into the mainboard, and verify 5 v is where it's supposed to be. But,.......I gotta go to the Shack to buy that cable, so I gotta stop for now.
 

Attachments

  • mustangbuild040.jpg
    mustangbuild040.jpg
    7 KB · Views: 293
  • mustangbuild042.jpg
    mustangbuild042.jpg
    7 KB · Views: 254
  • mustangbuild041.jpg
    mustangbuild041.jpg
    7 KB · Views: 318
  • mustangbuild038.jpg
    mustangbuild038.jpg
    7 KB · Views: 277
Subscribed. I'm very glad you're doing a step-by-step progress thread dedicated just to the MS. If (read: when) I decided to go to a DIS on my car, I'm sure I'll be referring to this thread a whole lot. Keep on keepin' on Mike!
 
Subscribed. I'm very glad you're doing a step-by-step progress thread dedicated just to the MS. If (read: when) I decided to go to a DIS on my car, I'm sure I'll be referring to this thread a whole lot. Keep on keepin' on Mike!
Well word to the wise,...the damn connector cable I need to hook the tester to the main board is obscure at best.
Best advice for tonight is to order the stupid thing from Amazon (what I ended up doing) before you ever solder a thing. :nonono:
 
Ok,...another week, another few hours to devote to the project. The cable I needed to test my progress came midweek. So....I plugged the soldering iron back in today.

The first way station is to check the power distribution circuit. It required that I add a few more capacitors and this little thingy that looked like a rectangular .50centipede :
mustangbuild046.jpg


After I get that done I open my newly purchased 3' DB37 male to female extension cable and hook the stimulator to the board:
mustangbuild043.jpg

I plug my newly purchased 9v battery into the stim and ck for power (5 v) in 3 places on the processor socket as per the instructions on the mega manual:
mustangbuild044.jpg


The processor socket is the 40 pin thing you see prominent on the circuit board. Power checked out like it was supposed to, ( yay me) so I unplugged it all, and got back to soldering.

The next several steps went along w/ the goal being a communication test. This EFI system uses a DB 9 serial port to communicate w/ the computer, so unless you have a really crotchedy laptop that actually has a serial port, you'll have to use a USB to serial adapter (almost every one available out there is frowned upon as "non-workable) The one I had has been with me forever (Radio shack) and works like a champeen on every thing I've needed it for. There are a few out there that are capable, and MS links you to one that they endorse, just be aware that this will be a problem you'll need to deal with.

The instructions require that you download a communication program to test the workability of the DB 9 serial com port and it was kinda confusing for a while, but after I finally pulled my head out,...I got it working
mustangbuild045.jpg


The test just confirms communication by typing a character on your keyboard,...it flows out of the USB port of the laptop, through the adapter, through the serial connection, back through the adapter and shows up on the keyboard.
Bottom line............If you type a letter "A" and it shows up on the screen..............you get a cookie.

Mmmmmmmmmmmmm........cookies.

15 more steps involved several additional capacitors, resistors, and a couple of jumpers. You temporarily plug the processor into the 40 pin socket and you get to actually burn the current firmware into the chip, and see the tuning software for the first time:

mustangbuild047.jpg

Downloading the current firmware, the programming software, the bootloader and figuring the proper sequence and parameters to get the chip to accept the new firmware took another half hour,.....after I figured that out,.......it took 20 seconds to upload the latest firmware into the processor.

mustangbuild048.jpg


The tuning software is actually up and running ( you can see the needles moving around on the gauges hunting for info that isn't there yet) The only gauge that is actually feeding back actual info is the volt gauge,...it's reading the power supply voltage.......which is the confirmation that the software is talking to the processor.

The last circuit I added today was the 4 bar map sensor. It actually soldered on the underside of the board. The yellow wire is the jumper supplied to enable the barometric correction circuit.
mustangbuild050.jpg


So that about wraps up todays' installment of How the Solder Burns,.....tune in next week for another edge of your seat episode.
 

Attachments

  • mustangbuild046.jpg
    mustangbuild046.jpg
    7 KB · Views: 272
  • mustangbuild043.jpg
    mustangbuild043.jpg
    7 KB · Views: 287
  • mustangbuild044.jpg
    mustangbuild044.jpg
    7 KB · Views: 285
  • mustangbuild045.jpg
    mustangbuild045.jpg
    7 KB · Views: 278
  • mustangbuild047.jpg
    mustangbuild047.jpg
    7 KB · Views: 283
  • mustangbuild048.jpg
    mustangbuild048.jpg
    7 KB · Views: 271
  • mustangbuild050.jpg
    mustangbuild050.jpg
    7 KB · Views: 275
very good write up mike. will you have to make up the entire tune or do they supply a basic tune to get you started? Just asking because with using my TWEECER RT you just build your tune off the factory ford EEC program. Keep up the good work