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MicroSquirt with 8' Harness
MicroSquirt with 8' Harness
MicroSquirt ECU by DIYAutoTune, MicroSquirt with 30, MicroSquirt with 8
MicroSquirt ECU by DIYAutoTune, MicroSquirt with 30, MicroSquirt with 8

MicroSquirt with 8′ Harness

5 out of 5 based on 8 customer ratings
(8 customer reviews )
MicroSquirt with 8' Harness



The versatile MicroSquirt with 8′ Harness: Standalone Engine Management System, Transmission Controller or CAN I/O Expansion Module- Version 3.0

MicroSquirt with 8′ Harness is an entry-level, fully assembled ECU and universal 30″ pigtail with varied applications targeting power sports, 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 with 8′ Harness 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 with 8′ Harness Transmission Control Options

MicroSquirt transmission control free firmware allows you to use MicroSquirt with 30″ Harness 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 & more…

MicroSquirt with 8′ Harness 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 MS3 or MS3Pro 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.

Customer reviews

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8 reviews for MicroSquirt with 8′ Harness

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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 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

    The MicroSquirt is essentially a scaled down MS2. Some features, such as the stepper IAC valve controller and low impedance injector drivers, are not included, but these are not particularly important on most late model Fords. 

    For wiring notes, please see the MicroSquirt Hardware Manual. We recommend two QuadSpark ignition modules when using stock Ford pencil coils on a V8.

    This is a standalone ECU, although you would need to keep the stock ECU in place if you wish to run the factory gauge cluster. See this article for what is needed to keep the stock ECU functional.

  2. 0 votes

    While the MicroSquirt can run fuel and ignition on LS series motors, this takes it about to the limits of its available I/O, and some features, such as the stepper-type IAC valve, are not supported. Depending on your needs, an MS2 with custom mods or MS3 may be a better choice. I recommend contacting our tech support department; we will be glad to go over this project in more detail and help determine which system would be best for your build. We'll be able to come up with a package that can completely replace the factory ECU.

  3. 0 votes

    You'll need the calibration data for the T-MAP sensor, but this should be no problem. The main limitation is that the MicroSquirt does not have an output for a stepper IAC valve; you could convert the motor to use a 2 wire design like the one off a mid-'90s VW.

  4. 0 votes

    You can download the software from our Software & Downloads page.

  5. 0 votes

    It can run fuel and ignition, as long as you are using high impedance injectors. It would not run a stepper IAC valve but can run a two wire PWM type valve.

  6. 0 votes

    The MicroSquirt can definitely run a small block Ford; the main question is what features you are looking to add over your current ECU. I have emailed you to discuss this in more detail.

  7. 0 votes

    We have a number of customers with ITB and boat builds, although usually not at the same time. There are a couple approaches to load measurement that you can use here. You can run a vacuum line from all eight runners to a canister and run that to a MAP sensor. For engines with a lot of cam, you can use a TPS for fueling.

    You can control where on the warmup curve is considered fully warmed - or use a cylinder head temperature sensor instead of coolant; this may be a more reliable measure of engine temperature in your situation.

    The MicroSquirt can have up to four spark outputs and will also support most distributors that you can run on this engine. Wasted spark would need a crank trigger or similar method of cylinder identification. A QuadSpark ignition module and two IGN-4 coil packs would work great.

  8. 0 votes

    Please contact our tech support team with details of what shift solenoids are used in what gear and how the selector inputs work. We'll check if it matches an existing pattern.

  9. 0 votes

    There isn't a good way to install BIP373s inside the current generation MicroSquirt. A good option if you want one direct coil control output is to use a Chevy Vortec ignition module.

    You can use the flex fuel or spare ADC inputs to trigger launch control.

    Currently, there are no special order modifications available for the MicroSquirt as they have a standard feature set.

  10. 0 votes

    The MicroSquirt can read a Hall effect sensor without any trouble. It will need an external ignition module for coil control. Most stock VW ignition modules are supported.

  11. 0 votes

    Here are your ignition options for this particular engine with a MicroSquirt.

    1. Use the standard distributor and only control fuel.
    2. Weld or pin the advance mechanism locked and use the MicroSquirt to control timing.
    3. Swap to an '82-'83 L28ET distributor and use either the stock trigger disc or our drop in L28ET trigger disc. This will require other changes to fit.
    4. Go with a crank fired ignition.
  12. 0 votes

    It can run on/off VTEC, but not the continuously variable iVTEC setups that were used on later motors. The continuously variable systems need an MS3.

    You will also need a different crank trigger if running MicroSquirt on an R series.

  13. 0 votes

    Here are the main sensors you'd need.

  14. 0 votes

    Yes - it would just need a tach signal from your ignition system, along with a MAP sensor, coolant temperature, and air temperature.

  15. 0 votes

    Running a MicroSquirt on a distributor is straightforward enough. There's just enough I/O to run a six cylinder in wasted spark with idle and A/C control as well. You might be able to get one of our SR20 or L28 trigger discs in the distributor if you want to go coil packs - if not, you could use a 36-1 crank trigger.

  16. 0 votes
    There are no answers for this question yet. Answer now
  17. 0 votes

    Yes, most of these Volvo engines used a very simple distributor that is easy to control with the MicroSquirt.

  18. 0 votes

    Please contact our tech support team with more details on what year / make / model this engine is out of so we can check the wiring diagrams for its ignition system. The VH45 was made for quite a while, and it appears Nissan used several different electronics packages with this motor.

  19. 0 votes

    Yes, the MicroSquirt can control fuel and ignition on this motor quite easily.

  20. 0 votes

    Yes, it can run this engine, although it doesn't have a ton of I/O. You can run the TFI ignition, idle speed, plus a general purpose on/off output. It supports both MAP and MAF based fueling; you'll just need a MAP sensor sized for your boost level.

  21. 0 votes

    It can support the 4G63 ignition. Low impedance injectors will require external current limiting resistors or an external peak and hold driver box.

  22. 0 votes

    Injection with a MicroSquirt would be bank to bank; you'd need something in the MS3 family, or a DIYPNP if you're up for some soldering work, to get sequential injection.

  23. 0 votes

    It doesn't. This is intended for competition vehicles that are not used on public roads, and other applications exempt from pollution control requirements.

  24. 0 votes

    You wouldn't be able to do this with a factory SR20DET CAS disc, but you could do this with our bolt in SR20 trigger disc if it will fit your engine's CAS.

  25. 0 votes

    Yes. This would be set up using the generic wheel decoder, set for 6 primary teeth at cam speed and a second trigger active on every rotation of the cam.

  26. 0 votes

    At a minimum, you'll need engine speed (which you can usually get off the distributor), a MAP sensor, coolant temperature, and air temperature. Adding a throttle position sensor will give you more tuning options for acceleration enrichment. A wideband O2 sensor will make the tuning process a lot easier, although it does not need to be kept in place once the engine is tuned.

  27. 0 votes

    You will need an external ignition module like our QuadSpark to run the coils if the bike does not have a CDI ignition, or coils with built in ignition modules. The crank / cam trigger pattern is a separate question; you will need a compatible pattern.

  28. 0 votes

    Yes, it's quite flexible. If this truck has a stepper IAC, it will not drive that valve, but you could swap to a two wire IAC valve off a '90s era VW. It supports just about all Mitsubishi ignition systems. Contact our tech support if you have any questions.

  29. 0 votes

    Measure the resistance of the injectors with an ohm meter. If they're low impedance, 4 ohms or less, you'll need current limiting resistors or a peak and hold driver module. The MicroSquirt can do timing control here no problem, too. To add electronic transmission control, you'll need to daisy chain it to a second MicroSquirt.

  30. 0 votes

    Just load it with the MicroSquirt transmission control code and wire it up. The manual in that link will have the wiring diagrams for this transmission.

  31. 0 votes

    While most sensors give a simple resistance or voltage based output, wideband oxygen sensors are different. The Bosch LSU sensor combines a Nerst cell (like a narrow band oxygen sensor) combined with an oxygen pump that extracts oxygen from the exhaust to determine the actual air-fuel ratio. It requires a control circuit to drive the pump, and none of its outputs are anything you can plug into a simple analog-to-digital converter and get a reading you can convert to oxygen levels. So a wideband oxygen sensor requires a dedicated controller circuit. As this circuit is not built into Megasquirt, you will need an external control device like an Innovate LC-2 to convert its output into a signal that Megasquirt can read. The gauge, however, is not required.

  32. 0 votes

    No hardware mods are required for this particular install. See the Nippondenso CAS notes in the MicroSquirt Hardware Manual; the 13B is very similar. Email us if you have any questions.

  33. 0 votes

    It should be a pretty straightforward install - email us with details about the crank trigger pattern and our support team can check if there are any likely issues.

  34. 0 votes

    Yes, this can use the factory Honda sensors - even the MAP sensor if you don't need an upgrade for more boost. The one sensor that I would recommend changing is that I'd recommend adding a wideband O2 sensor if you're tuning it yourself. The MS2/Extra Setting Up Manual covers how to create a startup tune - most of it is pretty straightforward, and our tech support can help out if you get stuck.

  35. 0 votes

    It can run a 3 cylinder with the injectors all firing in one group, although you'll want to temporarily get an O2 sensor on there somehow for the initial tuning stage.

  36. 0 votes

    Yes, you won't be the first to run a modular motor with one. The MicroSquirt has a maximum of four spark outputs so it would need to either fire the coils in pairs or use coil packs. Fueling will be bank to bank.

  37. 0 votes

    You can use a MicroSquirt here, although there are a couple limitations:

    1. The MicroSquirt does not have support for the factory crank and cam triggers. You would need to run an additional crank trigger.
    2. This engine uses a stepper-type idle air control valve. The MicroSquirt does not have an output for this.
    3. If this Jeep has a 4 speed automatic instead of a 3 speed, that needs electronic controls. Currently your best option would be a parallel installation with the stock ECU running the transmission and our ECU running the fuel and ignition.

    Stepping up to an MS3 may be a better idea if your budget allows; it would support the factory idle control valve and crank / cam triggers.

  38. 0 votes

    Yes, it can control fuel, ignition, and the idle speed control valve. There will be two outputs left over that can be used for boost control, cooling fans, etc.

  39. 0 votes

    You would need to run the coils in pairs, and swap to the later M20B25 crank trigger setup to use this combination, in addition to using a MAP sensor sized for your target boost level. Once you have added these parts, you can use a MicroSquirt on this engine.

  40. 0 votes

    Yes, this ECU can supply up to four spark outputs. For a 4A-GE distributorless ignition setup, I recommend swapping to the cam angle sensor off a Japanese market AE92 4A-GZE motor; it's a bit easier to use with distributorless ignitions (and you have no distributor cap with empty terminals cluttering up your engine bay).

  41. 0 votes

    Not much. On a typical install, you'll want to remove the vane air flow meter, so you'll want a GM type intake air temperature sensor and a MAP sensor. A wideband O2 sensor is going to be good for tuning as well.

  42. 0 votes

    It can run this engine as long as you use our QuadSpark ignition module and a cable operated throttle body.

  43. 0 votes

    We have had a number of customers run this on Subaru motors. It supports both 6/7 and 36-2-2-2 trigger patterns. We don't have a ready to go tune for this particular ECU, but the MS2 Setting Up Manual covers how to put together a startup tune, and if you run into trouble, we can go over your tune and data logs of the issue by email.