Oochi

So this is what I am looking at now. I still have to decide on the U3 U7 dilemma but idk which is better, easier. More reading will come. But other than that and the map sensor thing on the bottom, that looks like pretty much everything right?

Joe Perez

iTrader: (8)

You don't need the two large resistors on the heatsink, either. They're part of the fuel injector circuit you're not using.

You do need either U3 or U7, depending on which circuit you use for the crank input. I suggest that you install U7 and run jumpers from "TachSelect" to "VrIn" and from "VrOut" to "Tsel". (Don't forget to adjust R56 for ~2.5v at R54, and turn R52 to about one full turn clockwise from fully counterclockwise. This will create some hardware latency that you'll need to correct for in software.) I believe that you'll also need a pullup resistor from 5v to the side of R45 which is towards VrIn.

You can go ahead and install the three LEDs. They're kind of pretty.

Nice job of soldering, by the way. It looks very clean.

Oochi

Thanks Joe, it's my second time soldering, and I have a $5 harbor freight iron lol. I'll take the two resistors off of the heatsink this weekend and install the U7 stuff. And how do I go about adjusting R56 for ~2.5v at R54 for sure?

Joe Perez

iTrader: (8)

Just turn it with a screwdriver while probing between R54 and GND with a voltmeter.

You'll need to do the same on the MS3X board for the cam input, though I don't have the schematic here in front of me and so I can't remember exactly which resistor it is.

Basically, you're just setting the trigger threshold for detecting the cam and crank sensors. They swing from appx 0-5v, so we're setting it in the middle. It's not important to be exact here, anything in the neighborhood of 2-3 volts will be sufficient.

WestfieldMX5

You're clearly not listening to the advice given here.
You're clearly not reading the manuals, so I'm not going to bother

Braineack

iTrader: (62)

uhhhhh... what dilemma, I mean you've populated the entire board, might as well populate those too. U3 is required to use the opto circuit and has about 6 other components needed in conjunction with it, all look populated. U7 is for the VR circuit and has about 20 other components needed in conjunction with it, all look populated. So I mean, install them both...and pick which circuit you want to use...

At this point I'd use the VR circuit, so you need U7. That means you dont need: d1, d2, c30, c12, u3, r13, and c11... get it? but you have some of them installed.

Our writeup and diagrams were to try to prevent these useless components to be installed.

for example: your ms3x card will take care of the spark and fuel circuits, so you dont need to build them into the mainboard.

Most things should end ultimately end up on the expander card, like your idle, ebc, fuel & spark, cam input, etc.

The only real difference between my component map, is that I am utilzing the opto circuit for the crnak input, where Frank's is setup to use the VR circuit.

I'd suggest going to megamanual.com, and clicking on v3 DIY mainboard, and it shows exactly where component resides and in what circuit is it for. There's a method to the madness.

Oochi

Thanks!

I am sorry sir. I read a ton of stuff on doing MS2 for a long time and when I decided to go ms3x it pretty much confused most of what I needed to do and the differences in the boards, and also what the 3x card will take care of. I understand your frustration, I am new to all of this and still trying to figure what needs to be done. My apologies.

Thanks for the advice brain. Like I said, I am still trying to figure out what the expander card takes care of and what on the board controls what part of the car, which i should have looked into before buying, I just changed my mind from ms2 to ms3 too quick. I followed the directions that diyat sent me, which I saw the other instructions too late. But I really appreciate you all that are dealing with my ness

Oochi

OK, quick update. I finally got to work on it a little more. Removed the 2 resistors on the heatsink that i shouldn't have installed (among many other things I shouldn't have installed), installed the map sensor, completed the U7 circuit. Now I still have to adjust R56, jump S12C to JS9, look into making the harness, which ms3x wires I need and which I don't. And installing the daughter board and expander. I Also received my 64 pin connector from mouser electronics ($20 shipped).

Braineack

iTrader: (62)

looks like it's ready for miata specific input/output mods.

Oochi

Question on this, I have spare 1k ohm resistors i was going to use one as described in westfield's guide, but mine is 1/2W. May be a dumb question but I just wanted to make sure.

Braineack

iTrader: (62)

that's fine.

Freaky Roadster

That's looking better, nearly finished.

Freaky Roadster

When you have a moment please

WestfieldMX5

For the main board, measure the voltage between R54 and pin 3 of U7 while turning R56. On the MS3X board, measure between R17 and pin 3 of U7 while turning R11. In both cases, you want to see about 2.5 to 3 volts at that point, which puts you right in the middle of the actual output range of the sensors.

Freaky Roadster

Many thanks, also found it on your website, should have double checked that

Oochi

In my case, the harness should look like this, right?


Edit: On this pinout, I bought the 64 pin connector, but this diagram is for the 48 pin. I would assume I just leave the middle section out and just fill in the outer two sections according to the diagram? Also, How do I know what is needed out of the mainboard and what is needed out of the expander card? Thanks for help. I have attempted searching, but haven't found anything regarding ms3x

Freaky Roadster

Here ya go.

http://www.msextra.com/doc/ms3/hardware.html#wiring

Write a list, start with everything that is definitely connected to the 3X, injection, cam, idle, spark, etc
Everything else from the V3 board, IAT, coolant fuel pump, o2

jasonb

having just finished my first ms3 w/ ms3x i can attest to the fact that it is hella confusing for a noob on what components are required and also what components go with what mods. I ended up soldering in most of the stuff even though i'm using the expander but i still managed to leave out q22 and q23 so my crank input didn't work. duh.

people here have been saying to check out megamanual for schematics etc, but i found the msextra schematics very useful when checking my VR input (crank) stuff. towards bottom of this page: http://www.msextra.com/doc/index.html

Definitely stim that thing. the stim is awesome as a confidence booster. you can twiddle all the inputs and see them move on tunerstudio.

i'd also recommend using the usb connector on the cpu board. works perfectly for me. also worth mentioning that if you have any can bus devices you will need to run 2 wires to connect them up to the db37 (in my case my dash is can connected).

edit: ms3x connector is listed on the link i gave above. or here if you are lazy:: http://www.msextra.com/doc/ms3/hardw...ml#wiring-ms3x

Oochi

Thanks for all the help freaky!

Interested! Do you have pictures of it completed? What year is your car? And would you be willing to part with the stim?

On a different topic, I need to reassure this: In step 22 of westfield's guide it says
Step 22: install a jumper from S12C to JS9. Ignore the rest of the instructions in this step
But in the megamanual, it states that:
DO NOT INSTALL THIS JUMPER FOR NON-MegaSquirt-II APPLICATIONS - IT WILL DESTROY THE PROCESSOR!!
I would think this isn't a problem since nobody has said anything about it and it is in fact in westfield's guide.

Also with the 90-93 fuel pump circuit, referring to this picture:


the 3rd lead on the transistor is connected to the same spot as that jumper that I just mentioned above. Would it be reccomended to connect both the jumper and the fuel pump circuit to that spot? And if Anyone has any other pictures of their fuel pump mod, i would appreciate seeing those. but other than that mod, there really isnt any other mods I need to worry about right? Not keeping ac

jasonb

my car is a freak so my ms3 is built for a sr20det. I have to say you are very lucky, there is a lot of depth of knowledge here. in my situation there basically isn't any ms community for sr20's yet (firmware to support cas is now 10 days old).

i'll send you my stim and power supply if you will return it when you are done. its worth noting that both of us are using ms3x which means the stim doesn't see those outputs. it can generate all of the standard inputs though (crank/clt/o2/mat/tps/etc).