Microsquirt install wiring question
 

This is going in my 91 1.6. I finally got all my sensors in and ready to be wired to the microsquirt. I have the microsquirt mounted nicely in the stock ecu location. In the official microsquirt how to documents it shows how to wire your ignition to control the injectors and turn on the microsquirt unit using a main relay to provide power.

My question is, do I need to wire it completely new with bypassing the stock harness and run my own relays and inline fuses? Or can I just use the stock wires already ran in my car as it already had a main relay and fuses inline to protect everything?

I already used All Data at my work and have a complete pin out of the stock ecu and there color and there function. I have searched here and on the web in general but find nothing on the topic at least dealing with miata's. Any help would be much appreciated as I am now just waiting to wire it up and see if it starts. I do realize that the directions for the microsquirt are geared more towards something that's non efi and basically is like starting from scratch.

I am just very cautious. I know this was alot cheaper then a pnp units but it was still close to $400 and I don't want to hurt it.
Thanks for your time, Bill

at $400 I would have built a DIYPNP kit.

there's still plenty of external circuits needed to use a microsquirt.

I understand the fact there is more work then pnp. I figured either way, build DIY pnp and spend time soldering and building or just make the microsquirt work. I have no issues wiring it up in my car, I was just unsure if I could use the stock wiring or just run my own as per the directions.

I did find a few threads on here on using them and I did toss around the idea of a diypnp but was just unsure of my solder skills on small circuit boards. Plus I was told the microsquirt is a exact copy of a ms2 that's why I went this route.

the diypnp would be a lot easier to just make work over trying to get a bare microsquirt module to work.

the diypnp also runs off the microsquirt module but has a circuit board with all the extra circuits needed to input/out from the module:

https://www.miataturbo.net/attachmen...ine=1410274198

populating the DIYPNP circuit board takes about 30-45 minutes.

Then you just need to wire up all the jumpers from the circuit board to the connector board for your application. Most of the above is unused, but there are still plenty of things that require external circuits from the module in order to work properly.

Things that come to mind are the MAP sensor, any outputs beyond using ALD and WLD, any inputs like the clutch switch or a/c switch. Then there's things like the 5v circuit, pull-up, flybacks, etc.

the DIYPNP costs $425 and can be assembled, flashed, and installed within 2 hours.

from the microsquirt module page itself:

The DIYPNP is far from small soldering, 99.9% of the components are really resistant to excess heat from newbie soldering. You could put the thing together with a 1/4" chisel tip if you wanted...

Sounds like a lot of unnecessary work, for fear of a little soldering.

You can use the stock wiring like the DIYPNP does, but your probably going to have to build most of the board you see above, on your own, especially if you want I/O, boost control, launch control, etc..

looking again, you could probably make it happen pretty easy.

But you'd need a breadboard to make pull-up, flybacks, the MAP sensor, and any extra i/o's easier to handle.

and then figuring out how to mount a serial port in the stock ECU case.

I appreciate your guys input. I guess I made a $400 mistake. I thought that it would work for my application and even asked several people but should have posted my question in the first place on this forum. I guess I will throw the microsquirt-v3 up for sale. I will just have to get the diypnp kit. I am not scared of soldering just never attempted circuit boards before. Thanks again for your guys information and knowledge, it is and was very much appreciated!!

I recently built a diypnp and the build took 15 hours including the time to source the parts and build the alternator control circuit (nb). If I didnt have to build the alternator circuit it probably would have been about 8 hours and I was working slowly and methodically, making sure every solder was beautiful.

If someone was speed building the board, they might be able to do it in two hours... but I'm doubtful because there is alot of time identifying parts and finding their location on the board, and double checking the directions, making sure each solder is perfect and trimming extra component wire.

I would seriously just sell the microsquirt and get the diypnp. It ends up being easier because they have all the directions in one place, including the startup maps and diyautotune support.

last DIYPNP I built took under 2 hours start to finish--including loading firmware/tune.

the only directions I follow are my pinouts. I've always wanted to timelapse a build; maybe one day.



OP: microsquirt v3.0? the microsquirt is currently at v2.2...

and the module itself is only $270. What exactly do you own?

the DIYPNP which in includes the microquirt module and everything you need to assemble a complete PNP ECU is only $425.

Sure, if you have don a ton and are building at the speed of a Chinese factory worker then yes, maybe.

Finding the location of the parts adds at least an hour for anyone who has not seen the board before.

Opening the kit, laying out the parts, assembling your tools takes time, as does getting the parts out of the tiny bags.

Then cross referencing the directions and double checking, probably two more hours for sanity.

Add a few breaks, maybe another hour.

There are roughly 300 total solder joints, so if those were all done in two hours, then 2.5 per minute. That includes bending/shaping the components to fit, clipping off the unused lead, cutting and stripping wire. Some of the parts are a tight fit.

Then there is the QA time where you are closely inspecting every solder joint.

Then add to that the time to assemble the box.

This is eight hours for a first timer.

I would love to see you do a time lapse in under two hours (from the time you open the box), but I wouldn't want to be the guy buying that unit! ;)

I've built plenty (number is over 50 DIYPNPs alone). I agree with some of your points. But take my time, don't spend an hour looking for holes I know by heart, and only populate nessecary circuits.

DIYAUTOTUNE has already posted their own. They said this was 1.5hr:

1.5 hours, but he still has to do the ecu header, all the wires to the extension board, build the box, and load firmware/tune. There is some trial and error getting everything aligned in the box which adds some time, if you havent done one before.

He saved time by doing larger component groups and using cardboard to hold them in place. I bent the ends over to hold them in place, which gets a little unruly on the underside, but all my componets are flush with the board and all the solders are nice looking. I saw a guy top-solder everything which would be faster still but look messy,imo.

I top soldered the whole damn thing in like 2 hours, besides the components where it's not physically possible. The jumpers took like 30 minutes, longer to strip the bits of wire. Some of the easiest soldering i've ever done, board is huge, components small, vias huge and pre-plated. Sucks solder thru like a boss.

This is an interesting pissing match. The box takes 5 hours, what with the 8 screws :jerkit:

Just trying to give the OP a realistic picture of what it might take. Not trying to argue with experienced builders, just giving him a first timer's perspective.

I forget that everyone on the internet is a genius supermodel who can build a diypnp in two hours while making love to his wife/gf.

This is what I have. It came with the 3ft harness and all the sensors and pigtails. I already installed all the sensors, Iac, cts, and map.

This is the exact same microsquirt I have except I bought one with all the sensors and pigtails. Not sure but it says v3 in the description so that's why I assume its a v3 version.

http://www.diyautotune.com/catalog/m...ess-p-131.html

How much you selling it for?

I paid $385 plus shipping. So I got $400 into it. I already installed the sensors so it will be just the microsquirt and the harness, map sensor and pigtail along with injector pigtails. It sells for $339 plus shipping on diyautotune. I am asking $325 shipped anywhere in the lower 48. It is new never installed and never powered on. Harness is still stock with no wires stripped and also new.

I see, it's saying it's like a ms2 on a v3.0 mainboard.

you could still make it work without a lot of effort; you just need a battle plan.