This Write Up is For a 90-93 (94-97 Should Be Similar) Miata.
What To Buy:
For this write-up I'm using the v3.0 board.
I order all my parts through diyautotune.com, a miataturbo.net forum sponsor.
Required Parts:
- Megasquirt II Kit
- This is the main assembly kit. It comes with the board, case, DB37 connector to build your harness and all the components you need to build a MS.
- USB to Serial Adapter (Tuning Cable)
- Required to use your laptop to communicate with your Megasquirt.
- PCBv3 and v2.2 -- Pullup Resistors 'ModKit'
- Extra resistors needed to complete the Spark out and Tach input Mods.
- MegaSquirt Wiring Bundle - 23" Long
- 18" MegaSquirt Pre-built DB37 Harness
- Wire bundle to build your DB37 harness. The MS-2 kit provides the connector, you need these wires to build the connector. The second link is a pre built (Highly recommended if you don't mind spending a little more). Note: all the wiring colors currently referred to on the DB37 connector diagrams on the Harness page are taken from the DIYAutotune wiring bundle colour codes. A chart will soon be written to decode the MegaSquirt inputs for Miata users
Optional:
- MSPNP IAT Sensor Kit - Steel Bung
- HIGHLY RECOMMENDED - Required sensor to remove the AFM or MAF. The kit has a bung to weld to pipes, extra wire and contacts to insert into the AFM/MAF harness for easy install.
- Boost Control Mod-Kit
- Mod kit for the Boost Control feature.
- Relay Control 'ModKit'
- Mod kit for an extra relay control
- PWM IAC Valve Control (TIP120) 'Mod-Kit'
- (Standalone Only) - Mod kit to control the idle valve when removing the stock ECU.
Highly Recommended Tools:
- Lead Bending Tool
- Helps bend leads for easy installation into the board.
- JimStim MegaSquirt Stimulator w/ Wheel Simulator -Unassembled
- Used to communicate with your laptop without the need of a harness in the car; lets you test your build and flash firmware.
- Good soldering iron
- Small Phillips screwdriver
- Cutting tool to cut wire and leads
Things to be aware of:
Building a MegaSquirt and successfully setting it up to run your car is no small task. The MegaSquirt ECU is extremely powerful and an extremely entertaining project to work on, however you will find that there are lots of minor differences between MegaSquirt setups and even in Miatas, depending on exactly what you need your MegaSquirt to do, how old your car is and what market it was produced for.
This is not a statement to put you off, there are lots of good resources available to get your Miata up and running on a MegaSquirt ECU, however you should familiarise yourself with as much of the available information as you can, this will certainly save you a lot of headaches later








