This is the index to the latest web-based version of the manual for the MegaSquirt® EFI Controller. It is updated frequently, and contains the latest information on assembling, testing, troubleshooting, installing, and tuning your MegaSquirt® EFI Controller.

For the Frequently Asked Questions and answers, click here.

MegaSquirt® and MicroSquirt® controllers are experimental devices intended for educational and research purposes. MegaSquirt® and MicroSquirt® controllers are not for sale or use on pollution controlled vehicles. Check the laws that apply in your locality to determine if using a MegaSquirt® or MicroSquirt® controller is legal for your application.

The links in the left column take you to the various sections of the manual, the links on the right take you to the specific subsections.

Introduction to the MegaSquirt® EFI Controller

Start here if you are new to MegaSquirt® EFI Controller, this contains important background information.

How the MegaSquirt® EFI Controller Works

This section contains fundamental information on how the MegaSquirt® EFI Controller works, and how it doesn't.

MegaSquirt-II™ Processor Upgrade

Here is information on the MegaSquirt-II upgrade daughter card.

MicroSquirt™ EFI Controller

Here is information on the MicroSquirt® fully assembled, reduced size ECU using MS-II.

MS-II Sequencer™ EFI Controller

Here are links to information regarding the MS-II Sequencer™ fully assembled ECU that can do sequential injection and individual cylinder fuel and spark trim.

The V3.0 MegaSquirt® Main Board

This section contains the information on the V3 main board.

V3.57 SMD Main Board

Information about the V3.57 SMD 'pre-built' MegaSquirt® main board.

Assembling Your v2.2 MegaSquirt® Main Board

This section contains the v2.2 main board assembly guide and troubleshooting information.

Schematics & Troubleshooting

Various MegaSquirt® schematics and other info for troubleshooting.

Wiring and Sensors

This section has information on external wiring and sensors for use with the MegaSquirt® EFI Controller. It is mostly for MS-I, for MS-II, also see the individual documents (above) for IAC, ignition, MAF, knock sensors, etc.

Injectors & Fuel Supply

This section contains information on selecting and using air and fuel supply components for use with the MegaSquirt® EFI Controller.

Tuning Your MegaSquirt™ EFI Controller

This section explains how to configure and tune MegaSquirt™ on your engine.
  • MS-II™ FUEL:
  • MS-II™ IGNITION:
  • MS-I™ (fuel only):

    • TunerStudioMS

    TunerStudio MS is the MegaSquirt edition of TunerStudio by Phil Tobin, a next generation tuning application. It provides the ability to configure and tune all MegaSquirt controllers and is 100% compatible with MegaTune INI files and MSQ's.

    MegaTune

    This section described the common features of Eric Fahlgren's tuning software MegaTune. It is the basis of the 'web help' (accessed by pressing F1 in MegaTune), so it may be worthwhile to make it available offline in your browser.

    Files

    This section has links to various code files, software, and documents in PDF format.

    MegaSquirt® EFI Controller & Rotary Engines

    This section is devoted to the specialized information needed when using MegaSquirt® on a Wankel rotary engine.

    Turbocharging and the MegaSquirt® EFI Controller

    This section is provides information useful when using a MegaSquirt® EFI Controller on a turbocharged or supercharged engine.

    Other MegaSquirt® Hardware

    This section is for information on non-B&G hardware for MegaSquirt®.

    MegaSquirt® Embedded Code

    Here are guides to writing, compiling, and loading embedded code to MegaSquirt®.

    Appendices

    Miscellaneous MegaSquirt® Information.

    MegaSquirt® and MicroSquirt® controllers are experimental devices intended for educational purposes.
    MegaSquirt® and MicroSquirt® controllers are not for sale or use on pollution controlled vehicles. Check the laws that apply in your locality to determine if using a MegaSquirt® or MicroSquirt® controller is legal for your application.
    ©2004, 2009 Bruce Bowling and Al Grippo. All rights reserved. MegaSquirt® and MicroSquirt® are registered trademarks.