Current car info:
2001 LS
Naturally aspirated – bone stock but with hard sport suspension (yellow bilsteins)

Build Phase 1:Build phase 2:Build phase 3:Phase 4:Phase x: (May be inserted as 2a or 3a) Upgrade suspension, wheels, tires.++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++
So, how is this going to work you ask?

I plan on maintaining this first post as an index. Each step in each phase will become a subheading with even further sub-sub headings underneath it. There will be no pictures in the index, only links to the actual post where I begin to cover that topic. You will be able to see what step I am on by looking for the underlined or highlighted heading.

Keywords: Miata , LS , 2001 , 2002 , 2003 , 2004 , 2005 , 2001-2005 , Turbo , Parallel , MS3 , MS3x , Sequential , retain Cruise Control , retain immobilizer , OBDII

 

Sounds like you know what you're doing. I would recommend cleaning the injectors (unless you know they have been cleaned). I found that made tuning a bit easier since AFRs would oscillate less.

 

A couple weeks ago I purchased a MS3 unassembled from DIYAUTOTUNE.com. Originally I was planning on doing the whole thing at work because I have access to all the proper tools and equipment, but I decided against that to avoid any accusations of impropriety.

I settled on a Weller soldering iron on sale at Fry's for $100 after rebate. (that reminds me, I need to send that darn rebate form in) It has a digital display, 50w. I will write the exact name down later. I also bought solder, some flux paste, diagonal cutters, small pliars, and assorted other tools. I will post my current cost at the bottom of this post when I get the chance.

I also bought a jimstim so I could test the thing. Or so I thought. Turns out I bought the stim expander for testing the MS3x expansion. I also misunderstood and thought I bought the kit that included the MS3x expansion which wasn't the case.

When I opened the box, I didn't realize I didn't have the jimstim, and when everything didn't look right I thought maybe I got the newest version and so I moved onto the megasquirt itself while I did some research.

All went well until I got to the transistors. Those darn small semi-circle transistors with the 3 pins have VERY little room for the solder to flow without touching. I thought I may have shorted them out, so I took it to work to talk to some experts. After using a solder sucker to clean the old solder out, we re-soldered the couple I had already installed on the board and metered each one and everything was fine. On the way home that day I stopped at Fry's and bought a solder sucker and dug my multimeter out when I got home.

I then "finished" the megasquirt at least to the power testing point. I moved on to the JimStim. Thats when I realized I had the wrong part. I promptly ordered the correct JimStim and decided to just make the expansion stim board since I had my workspace already set up and was in a good rythem.

I finished the board, showed it off to everyone I knew (because at this point my stuff is starting to look pretty darn good) and took a few days off to wait for the JimStim to arrive.

It comes in and I assemble it. Didn't take too long, only an hour or two of work. I had some problems testing it because when I am tired I fail at reading comprehension. Once I figured out what I was doing wrong I was able to test the JimStim and everything was grand. That is, until I did my final check of the main board before initial testing.

Thats when I go through my shipping box and realize that there is a distinct lack of pieces left to build another board (for the MS3 expansion card). I do some research and realize I am a bonehead. I place the MS3 expansion card in my cart online because I was low on funds. I then do a final check of the main board so I can start testing it for power etc. That is when I realize I am missing capacitor #C30.

I check with the guys at work and they don't have the capacitor I need, and Fry's was out of it as well. My choice was to spend $14 on a capacitor variety pack, or just buy the capacitor from DIYAUTOTUNE. Since payday was approaching and I still had a few pennies to rub together in the bank, I went ahead and ordered the MS3 expansion and the capacitor I need. Package should arrive Thursday.

On to the Harness. My initial thought was to buy a boomslang, but they don't manufacture the part I need. DIYAUTOTUNE has a DIYBOB but not for my model year. The next option is to buy the AEM extention harness which should solve my problem and then just cut and splice what I need.

I did find out that I may be able to buy the connector parts separately online for about $30-40, which would be nice considering I am in a DIY kind of mood lately. I also have made a million connectors in my day in the Marine Corps (Avionics on EA-6b Prowler).

So in regards to the harness, I am waiting to find out if anyone can help me with part numbers of what I need so I can build it up.

Provided I can get the part numbers and order it all up, I am considering making several harnesses since 2001-2005 parts seem to be hard to come by. I will be making nice and pretty wiring diagrams so others can duplicate my efforts and I will take lots of pictures, but that will be in its own post when I actually get the parts in my hand.

Anyone able to help me with the part numbers so I can order it up?

 

I'm trying to figure out what it is you're up to. You're building a Parallel MS for your 01+ car? What is the MS going to control?

 

https://www.miataturbo.net/showthrea...269#post756269

and same thing in PM form.

 

There are several phases to my build - each building upon the previous phase. End goal is 240-260hp reliable daily driver Miata.

I haven't decided what the stock ECU will control yet. The MS3x will control fuel, spark, boost, and maybe the idle and fans.

EDIT: Thanks Y8s!

 

Megasquirt 3 with expansion is built and sitting on my desk. I performed the following mods:

Assembly step #26
The reasoning I have behind this even though I plan on letting my stock ECU control idle was that for reason "e".

After consulting with Matt Cramer of DIYautotune.com I was advised to jumper S12C to JS9 as well.

I was able to find a USB to serial cable for sale at Fry's labeled "i-dot-connect" for about 20 bucks. The latest firmware was loaded successfully under windows.

I then booted back into MacOS to do the actual setup of the MS3x. Here is where I am having problems... I am able to move the pots on my jimstim and see corresponding movement on my gauges in Tunerstudio, with the exception of RPM. I am posting on msextra.com trying to figure that out now. On to my harness...

 

Thanks to the help of Y8s, I got the following information so I can build my "jumper" harness: (some editing)

The reason I am ordering everything x5 is so that people reading this thread can have a source of parts if something is on back order and samples are not available. Yeah, I am taking one for the team. After I have my confirmed good and functioning harness the remaining parts will be available to you all for the cost of the parts plus shipping.

I was also referred to www.wirecare.com to make my harness pimp. I cannot decide which braided sleeving I will use - help me make my choice... http://www.wirecare.com/Braided-sleeving.asp

I want my finished harness to resemble THIS:

As parts arrive I will update with wiring diagrams.

 

Chiburban, I got some bad news. The 1123043-2 is NOT what you need. It can be hacked to work but I just got mine and for whatever reason, they don't put pins in the smallest connector location!

Here's what you gotta do:
Figure out what OEM harness pins you need.
(there are more than enough spare for most installs)
Cut the backside pins just before they make the 90 degree bend.
Reach into the connector entry side with a pair of needle nose and pull the spare pins out.
Take the pins you pulled out and push them into the required locations in the header.

Here's a list of pins that I used. Light gray text is for unused circuits.

https://docs.google.com/a/y8s.com/sp...=1&output=html

 

Thanks for the heads up. So the 3038 model seems to be the correct one now?

I am waiting till payday to order the remaining jumper harness parts. I have taken a break from the MS as I was overheating my brain.

 

yeah looks like it. I have the 3038 and it's fine.

 

Had some problems getting my stuff from onlinecomponents.com because the 1123042 ECU side connector wasn't stocked anymore. You would think they would call me to fix the order...

Anyhow, I have one in stock (sample) so as soon as my remaining parts arrive I will be building up my jumper harness.

 

Additional connector parts should arrive Wednesday.

MS3 is built, but still has the +5v jumper on the VR - I believe I will be taking that off before putting it in the car?

So far it looks like I will be letting the stock ECU handle:
EGR coils
Generator/alternator
immobilizer (leaving fuel pump on ECU in case thats how it Immobilizes)

I will be sharing some sensors etc, but everything related to performance including idle should be controlled by MS.

I will post a more detailed list later. I was originally going to use braided wire bundling, but cheaped out and went with heat shring tubing considering this is my first try and I will likely be tearing the harness apart at some point. If it works perfectly I will probably keep it for a spare or sell it to someone who wants to do the same thing. I have parts to build 6 more. (when my stuff arrives Wednesday)

 

why would you take off the jumper?

 

I was wondering about that actually. I am pretty sure someone told me I would have to remove that 5v pull up before I installed it in the car but I see it is on the Westfield build link. I guess all I have to remove is R7 then?

 

As far as I'm concerned you need the pullup. Else the sensor will not operate.

 

Now I found where I read the part about the pullup. Its tough because I have two people I trust and respect telling me (what seems to me) opposite things.

The Westfield Miata build keeps the jumper, but that is standalone...

[Brain, can you give me the ability to edit my first post? I want the ability to update my progress and add links to subsequent posts.]

 

Car side 72 pin connector is a bitch. Any suggestions on how to solder it all up? I have been tinning the wire and pin, and then laying the site on top of the pin and using the iron to flow solder between the two to get a good joint.

It's not going well. I completed 5 pins if like 60 something and I am not happy with the result.

Ideas?

 

 

Joe is probably correct.