Technical Articles

MegaSquirt Information And Technical Help

Note — these are here to help guide you and provide information. As with anything involving electronics, computers, and cars bad things can happen without proper research and planning. Do your homework. We cannot be responsible for any of your actions or their results whether based on this information or not. Be smart, and be safe… and for goodness sake, don’t blow your car up!

Featured Articles/Videos


Upgrade an existing Microsquirt to the new MS3Pro Mini.

In this article, we will show you how to modify your existing Microsquirt harness and get a HUGE upgrade to MS3Pro Mini.

Learn how to set up your generic outputs! MS2/MS3, Part 1: Basic.

In this article, we will show you how to use a generic output to turn on basic devices such as cooling fans, second fuel pumps, or other on/off devices.

Learn how to set up your generic outputs! MS2/MS3, Part 2: Advanced.

In this article we go over using port statuses and bitwise operations for complex setup. This is handy for creating new functionality. Do you want to activate a dump solenoid when on the 2-step? Want to use a single button for both scramble and bump? This is the guide for you!

The EFI Tuners Guide – Learn How Electronic Fuel Injection and Ignition Systems Work!

It’s like a free education in EFI.  This guide, written by founder Jerry Hoffmann starting in September 2022, will be continually added to over the coming weeks/months.  Check out the Table of Contents for topics covered currently, and topics to be covered.  Our goal is to help you understand EFI and automotive performance, and to help you know what it takes to be successful, so you can tackle your projects and come out with a HUGE smile on your face.  Come on, jump on in, the horsepower is nice!!!

Laptop Tuning 1967 Camaro Drag Car with MS3Pro using USB-2920 USB to RS232 Adapter 1

MS3 and MS3Pro Failsafe Features

A Look Inside MS3Pro Ultimate’s Programmable Peak & Hold Injector Driver

Click here for the full tech article on this topic.


MegaSquirt and MS3Pro/MSPNP Tuning Tips

Check out these articles, some internal, some customer/reseller contributions, to learn some Engine Management Tuning Tips and Tricks!



MegaSquirt Installation Writeups

From DIY Plug-n-Play setups to starting from scratch to build your own harness, and from factory EFI conversions to MegaSquirt to carb-to-EFI conversions. These articles are being gathered from around the web to give examples of how people are implementing the MegaSquirt ECU on various vehicles. Some contain very detailed technical information and wiring diagrams, some are more general in nature. If you know of an article that should be featured here email me a link at [email protected].

Documentation for current DIYAutoTune Hardware

Here you will find manuals for devices which were either designed by or are not official Bowling & Grippo products, not covered on the MegaSquirt documentation. These are supported through directly.

Legacy DIYAutoTune hardware documentation

These items are no longer in production.

We no longer actively support the MS1-based eMS-Pro except for original purchasers of units bought through DIYAutoTune (be sure to have your receipt information ready before contacting us). For eMS-Pro tuning, also see the MS1/Extra documentation.

Installation and Wiring

Tuning and Settings

Internal ECU features and troubleshooting


Project car archives

These installations do not always use current parts, firmware, or settings.

MegaSquirt and related Technical Videos / How-To’s

Customer submitted tech articles

Tips, tricks, and cool installations sent to us by our customers.

Other articles we found on the web you might find interesting

Want to learn more about Engine Management Systems and Tuning?

Pick up a copy of Performance Fuel Injection Systems by our own Matt Cramer & Jerry Hoffmann.

HP1557 - Performance Fuel Injection Systems

DIYAutoTune is an MegaSquirt EMS/EFI manufacturing and distribution company. Our main offerings include: MegaSquirt Plug-N-Play Engine Management System Kit, the MS3-Pro engine management system, our MegaSquirt-I system, MegaSquirt-II, and MegaSquirt-III Assembled and MegaSquirt-III unassembled versions, Weather Pack kits and other wiring components, as well as carrying fuel injectors, fuel pumps, wideband O2 sensor systems, and more. Check out our online catalog for the full lineup.
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