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MicroSquirt Engine Management System with 30″ Wiring Harness

5.00 out of 5 based on 2 customer ratings
(2 customer reviews )


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SKU: MicroSqrt3 Category: Brands: ,


MicroSquirt Engine Management System with 30″ Wiring Harness

Version 3.0

The versatile MicroSquirt: Standalone Engine Management System, Transmission Controller or CAN I/O Expansion Module

Microsquirt is our entry-level fully assembled ECU with varied applications targeting power sport single cylinder all the way up to 8 cylinders with up to 2 fuel and 4 spark outputs. Over 40 different ignition modes are supported from mainstream applications like GM LS1, Ford Zetec, Bosch Motronic, and Chrysler Gen III Hemis to unusual modes like Renix Jeep and the Suzuki Swift GTI.

MicroSquirt Engine Management Software Features

-Supports speed density, alpha-N (TPS based), or MAF based fuel and spark tables
-0.66 microsecond injector pulse width resolution
-Allows blending multiple load types, including specialized mode for independent throttle bodies
-Supports a wide variety of OEM cam and crank position sensors
-Accelerator pump or model based acceleration enrichment
-Closed or open loop idle speed and boost control -On/off nitrous control
-Wankel rotary support: 2 rotor engines with separate leading and trailing spark tables
-Staged injection
-Table switching
-16 x 16 fuel and spark tables
-2 step rev limiter (launch control) with no-lift shifting
-Wideband AFR target table
-Flex fuel sensor input
-Real time barometric correction (external sensor required)
-Sequential shift cut and air shifter control

MicroSquirt Transmission Control

MicroSquirt transmission control free firmware allows you to use microsquirt to control a number of electronic automatic transmissions (gearboxes). It can work standalone or integrate with one of our ECU’s over canbus.

Control applications: GM 4L60E I GM 4L80E I GM 4T40E I GM 5L40E (dev) I A341E I 41TE (dev) I Ford 4R70W I Ford E40D (dev) I Subaru W4A33

MicroSquirt CAN I/O Box Expansion

Microsquirt I/O Box firmware allows you to use a Microsquirt as a plug’n’play I/O extension box for the MS3 or MS3-Pro ECUs. It can offer a useful I/O addition:

-7 Analog inputs (0-5V variable)
-2 Wheel speed inputs (VR or hall type)
-2 Wheel speed (hall type) or ground-switch inputs
-1 dedicated ground-switch input
-2 high current PWM/switch ground-switching outputs
-4 mid current PWM/switch ground-switching outputs
-1 low current PWM/switch 0-12V output
-Perfect for capturing and logging vehicle speed and additional sensor data (e.g. pre- and post- intercooler temperatures, fuel pressure, oil temperature etc.)

To Use a GM 1, 2, or 3 Bar MAP Sensor with the MicroSquirt

In the illustration:

A is ground,
B is the sensor output signal to MicroSquirt,
C takes 5 Volts from MicroSquirt.

The pins are marked A-B-C on the sensor itself.

Customers' review

Rated 5.00 out of 5 stars
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2 reviews for MicroSquirt Engine Management System with 30″ Wiring Harness

  1. 5 out of 5

    Price is perfect and this little box can do a lotPutting this on my 1990 civic d15b2 to put nitrous on it and as the outputs are very limited it had everything i need and the car started immediately when i got it all wired up tho i had to fiddle with the timing settings to get it to run smoothly also have issues with getting enough fuel out on the top end but still if you know what your doing you can really do some amazing things with this little box.

    Was this review helpful to you? 2 of 2 people found this review helpful

  2. 5 out of 5




    Was this review helpful to you? 1 of 8 people found this review helpful

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Is this just for motorcycles and other small engines, or can it be used in a car or truck?

  • The MicroSquirt can run regular automotive engines; it's not just for powersports applications. It is possible to run this on a V8 in wasted spark, although it doesn't have very much I/O to spare for extra functions when using four spark outputs.

I've heard some people say it has two spark outputs and some say four. What's the deal?

  • It was originally designed for two spark outputs, but the MS2/Extra code allows you to use WLED and ALED outputs as additional spark outputs. You will need to add resistors in the wiring harness for using them with most coils.

Is it waterproof?

  • No, but you can make it waterproof with a bit of RTV silicone around the edge of the case.

Are there other versions of the MicroSquirt for other functions? Transmission control or the "IO Box", for example?

  • These all use the same ECU, just running different code to change its function and use it as a transmission control unit or I/O expansion device. See MSExtra.com for details.

Could I use two MicroSquirts, one running the engine and one running the transmission?

  • Yes. They would link up over their CAN networks to look like a single unit to the tuning software.

Where is this unit made?

  • They are built in the USA - electronics, harness, and case.

What do I need to tune this unit over USB?

Questions & Answers

  1. 0 votes

    It will work, but isn't ideal. There is not a good way to mount the MapDaddy inside the MicroSquirt case, and there is no enclosure for using the MapDaddy as an external sensor.

  2. 0 votes

    The Ford V6 is fairly straightforward. You will need a QuadSpark ignition module if running the stock coil.

    An MS2 V3.57 or V3.0 would be a better choice for the TBI. We do not recommend MicroSquirt on GM TBI applications as its injector drivers cannot handle the current that the very low resistance TBI injectors use without current limiting resistors (which slow down their opening times) and does not have an output for the stepper IAC valve. The MS2 can run both of these out of the box and is a better fit for TBI applications.

  3. 0 votes

    It's 4.66" wide across the mounting ears, 3.15" end to end, and 1.66" from back to the top of the connector without the harness plugged in.

  4. 0 votes

    This unit will have full control over fuel and ignition on this car. Stepping up to an MS3 will give you more advanced boost control, traction control, individual cylinder tuning, and other high end features.

  5. 0 votes

    Yes, the MicroSquirt can run an SR20DET. If this one has a distributorless ignition, you will need to add our bolt in SR20DET trigger wheel. Please contact our support team if you have any questions.

  6. 0 votes
    There are no answers for this question yet. Answer now
  7. 0 votes

    -40 to +85 degrees C is the minimum spec for all components in this ECU.

  8. 0 votes

    If it matches the trigger wheel shown here:


    The the MicroSquirt will have native support for this pattern. If the pattern is different, please contact us with a picture of the trigger wheel, and we will check if it can be used.

  9. 0 votes

    The MicroSquirt can run this engine with bank to bank fueling and distributor based or wasted spark ignition.

  10. 0 votes

    The MicroSquirt has only two injector outputs. Normally on a 3 cylinder 2 stroke, the system would use one coil that sparks all three cylinders at once, and the MicroSquirt software is set up to do this. It does not currently support 2 separate coils on a 3 cylinder unless they are triggered at the same time.

    It does, however, have boost control capabilities.

  11. 0 votes

    MicroSquirt ignition output wiring is covered starting in section 5.3 of the MicroSquirt Hardware Manual. If you have any questions, please contact our technical support department will full details of what coils you are running.

  12. 0 votes

    This system works with many cars that used Bosch engine management, but you will need to contact our support team to go over what is needed to run the ignition and some other features on this engine.

  13. 0 votes
  14. 0 votes

    This should work - just keep in mind the following limits.

    1. If your throttle body uses low impedance injectors, you will need current limiting resistors.
    2. The MicroSquirt does not have an output for stepper type idle speed control valves. If your throttle body has one of those, you could use a '90s era VW 2 wire valve instead.
  15. 0 votes

    This may be an odd fire motor, but it's not a particularly odd application - we have a number of customers using this ECU on Harley V-twins. It has two fuel and two ignition outputs, and supports many motorcycle crank trigger patterns natively.

  16. 0 votes

    We currently do not have an easy way of controlling direct injection systems - they run at around 50 to 100 volts, and need special voltage and current control circuitry. There have been some experimental installs with systems in the MS3 family using third party direct injector driver circuits, but this is highly experimental and not something documented well enough for others to duplicate.

    This would only be street legal if installed in a vehicle that predates emissions controls.

  17. 0 votes
  18. 0 votes

    The MicroSquirt can use any voltage based MAP sensor, and works with most automotive temperature sensors. It supports most brands of wideband O2 sensor controllers as well as narrow band O2 sensors.

    For software, you'll tune it with TunerStudio.

  19. 0 votes

    You could use one MicroSquirt to control the engine and one MicroSquirt to control a 4R70W or similar transmission. If running stock Ford coil packs, you will need to use our QuadSpark ignition module as well.

  20. 0 votes

    It ships with the current stable release of MS2/Extra. As of today, November 27, 2017, that's MS2/Extra 3.4.2.

  21. 0 votes

    It has a 2 step rev limiter - you can use the flex fuel or analog inputs to trigger this function. Full on rally style anti lag would require stepping up to something in the MS3 line as this is difficult to do without fully sequential injection.

  22. 0 votes

    That can work as long as you use current limiting resistors - the TBI injectors draw a lot of current. You can use GM air temperature and coolant temperature sensors and a GM style MAP sensor with this ECU.

  23. 0 votes
  24. 0 votes

    You should be able to get an RPM signal off the fuel points without much trouble.

  25. 0 votes

    Yes, it is able to work on rotary engines as well as piston engines.

  26. 0 votes

    This isn't the first lawnmower project we've seen.

    You will need air and coolant (or cylinder head) temperature sensors, an RPM input, and a MAP or throttle position sensor. A wideband O2 will make the tuning part of the build a lot easier. I'd typically recommend sourcing the fuel delivery hardware (injectors, throttle body, and fuel pump) off a fuel injected motorcycle or scooter for small engine builds.

  27. 0 votes

    You'll need suitable sensors. It will support GM, Bosch, or many other types.

    And a wideband O2 sensor will make tuning a lot easier. This assumes you already have a suitable fuel system (injectors, pump, etc).

  28. 0 votes

    The stock CAS will require something in the MS3 family. Using a MicroSquirt would require an aftermarket CAS wheel or crank trigger.

  29. 0 votes

    For tuning software, you'll want TunerStudio.

    Note that MicroSquirt can run the Honda ignition without an EDIS4 module, or even run a distributorless ignition triggered off the factory Honda distributor pickup. EDIS is rather unnecessary at this point - and may stick you with a rev limiter intended for a Ford 1.9 CVH engine. For more details, see the Nippondenso CAS notes in the MicroSquirt Hardware Manual.

  30. 0 votes

    We have not tuned one of these bikes in house, but the MS2/Extra setting up manual walks you through how to put together a base tune, and we can help if you have any questions.

    The MicroSquirt does not have per-gear sequential shift cut features, but this is available in MS3.

  31. 0 votes

    The MicroSquirt can handle the earlier on/off VVT, but for continuously variable VVTi you will need to step up to the MS3.

  32. 0 votes

    Yes, you can trigger it from a distributor, no problem. Some of the earliest MicroSquirt installs were on engines with distributors and no trigger wheel (other than what was in the distributor, of course), before they were even released to the general public. You will also need air and coolant temperature sensors, and a wideband O2 sensor will make tuning it a lot easier.

  33. 0 votes

    Yes. The MS2/Extra software calls this a secondary load method. This stacks two fuel tables that are either added or multiplied by each other.

  34. 0 votes

    It can run the fuel and ignition, but does not have a suitable output for the factory idle speed control valve on this motor or most other GM applications.

  35. 0 votes

    Yes, if using an E4OD, you'll need one MicroSquirt for the engine and one for the transmission. See these links for MicroSquirt wiring for the TFI ignition and MicroSquirt E4OD specific wiring.

  36. 0 votes

    Yes. Its main limitation on this motor is that it doesn't have an output to drive the factory IAC valve. See notes on the 420A in the MicroSquirt Hardware Manual for more details.

  37. 0 votes

    Yes, this includes a short wiring harness.

    The MicroSquirt is basically a scaled down MS2. The PWM current limiting for low impedance injectors and the stepper IAC outputs are the main features that didn't make the cut. The overall I/O is somewhat more than a standard MS2, but you can add somewhat more I/O to an MS2 if you add enough mods to it. A MicroSquirt, by contrast, is a standard package that is only built one way.

  38. 0 votes

    All you've got to do is wire it up and tune it. See the 4G63 / Miata wiring notes in the MicroSquirt hardware manual.

  39. 0 votes

    Yes. If you run the coils in wasted spark mode, you will have ALED and WLED free for functions like boost and fan control.

  40. 0 votes

    Yes, as long as you use a thermistor type cylinder head temperature. The MicroSquirt currently does not support thermocouples for engine temperature, but there are a number of suitable thermistor type CHT sensors out there.

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