• I have used this mod before and it really do away with any trouble you maybe having with the ignition on GM. It’s a great product and will use them from now on on any MS that I install.

  • Well this is just great. I remember making fun of megasquirt maybe 10 or so years ago. Now it’s just simply a beast. I run this in conjunction with a stock 2jz is300 ecu so I wired in one thing at a time progressivly using more and more features from the megasquirt. Combined with tablet tuning, custom tablet gauge layouts, auto tune, ability to use any kind of sensor inputs, and all kinds of tuning options this is really impressive. Dollar for dollar it puts other Ecu’s to shame. If you can deal with the diy type of install then there’s really not a better deal on the market.

  • Excellent ECU. Setup was fast, (plug it in, connect vacuum line, set base timing), and fire up. We had the cal roughed in on the dyno in about an hour. A must for any boosted Miata, or just one you want to drive better than stock.

  • This unit is a fantastic improvement over the stock ECU! The included base map was close enough to get me running with no issue, and after driving around for a couple of hours I took it to the dyno. Two hours later it was tuned to my mods (FM intake & exhaust, 525cc injectors) and putting down 223 HP/231 lb.-ft., with 150 lb.-ft. available at 3000 RPM, and 200 lb.-ft. at 4000 RPM. The MSM0405 provides a much smoother power delivery than the stock ECU – no more “light switch” powerband!

    John P.

  • Negatives:
    -PCB of lower quality (minimal PTH pad sizes and via annular ring, cheap solder resist)
    -Lots of non-standard footprints
    -Some components supplied are different from the footprints on the pcb
    -Feels a little amatuer if you are used to higher quality electronics kits

    -Components well labeled
    -Lots of features for the cost
    -Case is decent
    -Prototyping area on main pcb

  • Very professional, no reason not to buy these because they make the job easier. You get 5 different colours, 2 of each colour and all in a labeled, zip lock bag. If Diyautotune puts this much thought and experience into their simple stock items then imagine how good the bigger items will be.

  • This is so superior to anything available from MS suppliers in my country (they supply all wires in the same guage and colour, with paper labels) and delivery was exceptionally quick. This is loom form Diyautotune is designed to make your installation logical and easy, there is no good reason not to buy either this or the shorter 24″ one. Good tools let you focus on the job at hand instead of diverting energy to making the tools work for you!

  • When you see the care they take with even simple things like this, it confirms how professional this company is. All wires professionally cut and ready for you to connect, they were delivered in a labelled, zip lock bag and I am very satisfied with quality.

  • Ordered the PNP with multec injector clips, it is the nicest drop on harness I’ve seen to date and the customer service, packaging, and detailed instructions are second to none. Hands down would buy again and recommend. Alex Fornal

  • Jerry Hoffman – Tell me how you can fix this problem by adding another check valve, where would you install that? A properly installed fuel system has the pump go directly to the fuel rail, and the rail then goes to the FPR, and it bleeds excess fuel to the tank return. This is the way it is done so the excess fuel can cool the injectors.
    So where would you install the check valve? If you block the flow to the FPR, you get full pump pressure, no regulation. Reverse it and the check valve does nothing, the pressure still bleeds down. Put it after the FPR, same thing. The bottom line is a FPR SHOULD NOT LEAK DOWN, THERE’S A GOOD REASON WHY OEMS ARE NOT ALLOWED TO DO THIS.
    I didn’t spend a bunch of money on a Kent Moore injector test set to not be able to use it, nor am I going to install a push button switch for the fuel pump power in my dash in order to get my engine to start, this is total BS.

  • There are check valves that can be installed for an OEM-like maintenance of fuel line pressure when the pump isn’t running. This is very common for high flow fuel pumps/regulators though. I know when I fire my race car, which uses a pump/regulator combo that doesn’t hold pressure when it’s not running, that I either do one of two things. I either flip the main switch on an instant before I hit start (so the 2 sec prime does it’s job just fine) or I turn it over knowing it’s going to have to sync the ECU before it builds pressure, and then fires, which means it turns over an extra revolution or two.

    I’ve used other performance pumps/regulators and they generally behave the same, though there surely are exceptions out there I suppose. As best as I can tell they just work differently than OEM pumps, because they are designed to.

  • This is a great entry level ECU for applications where weatherproofing is a concern. It also works exceptionally well for transmission control or as an plug and play I/O extension for your MS3 or 3-Pro ECU

  • This is a great unit ! ( as are all of the Gen 2 PnPs) You really can be up and running in an hour. Add to that that DIY is one of the best companies that I have ever dealt with!

  • A true “Plug and Play” ECU it took me more time to install the box in the car than it did to get the car started. With a basically stock vehicle you really can be running in under an hour.

  • Possibly the best bang for the buck in the universal EMS world. The MS3 Pro has tons I/O, supports a huge number of native trigger patterns and has features for every type of racing and even creature comforts like A/C control! Superlative CAN Bus options let you talk with aftermarket loggers, other MS based hardware and OEM stuff as well. Plus support from DIYAutotune and the MS development team is second to none.

  • Wow great product, I added this to my MS3, added one jumper s12c to js9 plugged in two ribbon cables and just like that added more inputs and outputs than I will ever need enabling fully sequential spark and fuel. Awesome it fired my ez30D right up.

  • I purchased this with the 3x expander board and pigtails for a EZ30D in a wrx. Once I fixed all my wiring errors it fired up on the factory trigger wheels. This is the city MS install first MS3X. It really makes expansion very easy. Great product.

  • My son just purchased this for his 88 Thunderbird with a 5.0 HO stock 88 HO cam, SVO GT X heads and explorer intake with a T5. Install was very easy ( less than 1 hour) and the car started right up. The 3.3 firmware did have a bug that caused the car to shoot to 3500rpm for a few seconds, with a simple firmware update to 3.4 problem solved.The only improvement I would love to see is the com port moved to where you don’t have to remove the ECU to plug into it. The car does run better than ever and now we can upgrade cam and injectors and anything else with very easy tuning. Highly recommend!!!

  • This is by far and away the nicest, highest quality, most well thought out pnp harness I’ve ever seen or used. Mark Dalquist — Throttle’s Performance.

  • Great quality kit. Everything is very well labeled which simplyfies the build. All information needed for the build is very well explained on the DIYPNP website.

  • I don’t think I can ever say enough awesome things about the MS3pro and all the guys at DIY, any questions i’ve ever had they answered for me, the product itself has hands down the most “useable” features out there and the tuning is bar-none the easiest i’ve ever done. I’m dual VR crank and cam sensors, Full sequential 8 cylinder fuel and COP spark, Driveshaft speed sensors, boost control, 2step launch control, line lock staging control, fan control, staged fuel pumps, datalogging additional Oil pressure and fuel pressure sensors with the enable safety circuits around those and will be implementing the comparitive traction control this when I add a front wheel speed sensor!

  • Thank you for making an excellent product! In today’s day and age it is very rare to receive a part designed for racing and expert tuning that works as it should right out of the box. The Miata we installed your MSPNP-Pro into fired on the base map on the very first bump of the key. It was a very welcome sign for things to come for this car this year! Thanks again for the help and the superior products. I will definitely be back for more as needed!

  • My truck has been up and running on a MS3X system 6 months now. I bought the unassembled kit and put it together with no issues other than my eyes not being as good as they used to be – I had to buy a lighted magnifier to do the soldering. The kit is very well marked and documented and well worth the effort.

  • Just installed this in a Lexus SC400 manual transmission. It bolted up like stock, and the install was very easy. I spent more time installing the wideband then the megasquirt! I made a MSQ for the 1UZ and it fired up on the first try! Superb product, and even better customer service from Matt Cramer, who answered any questions I had setting up my basemap.

  • i buy about 15 ms2 from diy autotune and a lot of components.
    very good quality,fast service and fast answer for litle problems or suggestions.
    have a lot of cars and offroad runs with megasquirt,i am very happy.

  • I used this set to make a wiring harness without any extra wires in it. It worked amazing! I had no problem seeing the labels and if it was a dark color I just looked at a wiring diagram. overall these is a great product!

  • I purchased this unit, added the Mapdaddy 4 Bar Map sensor and Realtime clock. I had the unit in a couple weeks and had the car running a couple weeks after that. Granted, this was just the first build and a year later I have redone things a few different times (trying to clean up the factory wiring).

    Email support has been great plus the good support at MSextra and Corral have made this a very good experience. After-market ECUs are a lot of work and I have learned a lot about Engine Management from what I have done.

    This system replaced an Accel Gen 6 ECU that quit working. I’d recommend this system to anyone who wants to isn’t scarred about learning new things and will spend the time to make the most of their engine through proper management

  • This is a great kit. It was very straight forward to put together as there is plenty of documentation on how to get everything together and working.

    More importantly the guys running this site are great. They are enthusiastic about what they are doing, and very willing to help out.

    Can’t say enough good things about this site, the people or their products.

  • No mention of the requirement for a FTID TTL232-3V3 cable until you go to jb’s site. Would have been nice to order all at the same time.
    Love the JimStim.

  • It would definitely be nice to get SOME sort of documentation as to what the wires are with this bundle. The wires are good quality, but the print doesn’t stand out especially well on the darker wires (you’ll want a flashlight or workbench with a light to help identify them).

  • Another great purchase from DIYAutotune. Prompt shipping with insurance! Product came individually packaged like usual with everything labeled very well. Had this together in a couple hours and could not be happier with it.

  • Great product and pretty clear directions. I’ve never assembled anything quite like this and I would give it a 2 out of 5 for difficulty. Something anyone can really do as long as they are competent in following directions. I would recommend!

  • Para motores con sensor de cigüeñal (CKP) te recomiendo una Megasquirt II con PCB 3 o 3.5, con esta se logra hacer funcionar bien el motor, … ó una Megasquirt III con la expansión MS3X para que tu inyección sea secuencial, y puedas comandar el módulo de Aire Acondicionado, ralentí, etc….. personalmente mi iría por la Mega III, pero insisto la Mega II es suficiente para el motor del Lancer, si estas en México contáctame en DIAC Performance, somos dealers de Megasquirt, y tenemos una área de investigación y desarrollo de electrónica automotriz.

  • What a great kit! Had it together over the course of a weekend working on it on and off. Running MS extra 3.2.5 firmware. Kit was labeled perfectly and the instructions in the megamanual were clear and concise. I convinced a couple local racers to fuel inject their cars this winter after seeing my ecu put together so easily. Hopefully I will be doing a couple more of these this winter. Shipping again was extremely quick and insured.

  • Awesome kit!! Everything perfectly labeled. Anyone with minimal experience and who has read through the megamanual should have no problem identifying components and getting the unit together. Shipping was cheap with insurance and was delivered to me very fast. Looking forward to doing future business with diyautotune.

  • Si señor la ms3 te sobra es mas te podría decir que es mucho ya que varias cosa quedarían sin utilidad en ella, particularmente en ese modelo que no tiene distribución variable ya con la ms2 estas bien sobrado.



  • Paid for the ecu and it was shipped to me from across the country in two days! Wiring is all labled and easy to read. Manual is very well written. Half the price of an equivalant Haltech, plus the megasquirt has more outputs and all the features! Well built ecu and harness, great software, great service from diyautotune.

  • Awesome product! Ordered this one assembled. Nice soldering work done.
    I am using this stimulator to simulate a 4/2 CAS on a 4G63T DSM/GVR4 ECU. So much easier writing code at home than out in the garage burning fuel, and freezing my hands off in the winter, or doing 100’s of WOT pulls just to get something right in the code that requires going way up in the RPM range. This neat little device does all that for me. Plus so much more! :)
    This device can be made to work as a stimulator for many OEM ECU’s out there. You still need a eprom emulator to write code.
    Thank you DIYautotune for providing these great products!
    Yours, Kim H. From Sweden, Europe.

  • hola que tal, necesito un megasquirt para mi auto es un chrysler magnum turbo 1988 con SMEC computer. cual me recomiendan la quiero para ensamblar en casa how much it cost?

  • hola que tal, necesito un megasquirt para mi auto es un chrysler magnum turbo 1988 con SMEC computer. cual me recomiendan la quiero para ensamblar en casa how much it cost?

  • I agree with Mr Jon Dresser. The bunble is helpful but it fails because my eyesite isn’t as good as it once was and colour coding is much easier to identify than the tiny and sometimes poorly ledgible writing on the wire.

    PLEASE READ THIS. A written list included with the wire bundle would help to identify the wires much more easily.

    It’s a shame that 10 guage wire for wiring up the earth and power to the relay board isnt included. I would’ve paid extra for this to be included. Same with the injector wires. In this case, I ended up with a whole bunch of left over wires and many I don’t have…

  • Best bang for the buck! As you already know, MS is great. The ease of install with the PnP is awesome. I currently have the DIY Trigger Wheel and LS2 coils setup. I have configured my e-Fan to work with the ecu as well. No separate fan controller needed which saves money or the money you were going to spend on the unit, put it towards the EMS. With Boost control available, MS can control just about everything. It is great to be able to open your laptop and control a majority of components in one program rather than having piggybacks with separate controllers. The list goes on and on and so far, I have not used all of the features. To top it off, DIY’s customer service is great! Always there to help and courteous. Keep it up DIY!

  • even thow I’ve been a real pain in communications, Matt and DIY Autotune were great in answering and helping in getting the package delivered in time for further shipping to NL,
    now to get it in my hands and put it together, can’t wait to start using my crabs as a doorstop…..

  • I was amazed by how simple it was to build ! As said by other reviewers , the bags are labeled so well ,that its almost impossible to make a mistake during the assemby ! It took me 4 hours to get it complete in front of me ! Tested it with the stim and everything was fine !!

  • Excellent tool!
    If you remove the pin holding block, you can also use this tool to do an excellent crimp on other non-insulated pins like the Bosch injector plugs and Denso ignition coil plug that also have very similar seals that slip over the wire like the weather proof plugs but are a bit smaller. Much nicer using this tool for the Bosch and Denso pins than butchering them with pliers.

  • The MPX4250 is excellent value if you are wanting to run a boosted engine at around the 20psi mark, or if, like me, broke the original map sensor that was supplied in the kit haha

  • The 8′ wiring loom is excellent especially if u are splicing into the existing vehicle harness, all the wires are labeled in varying segments, only downside is that on the brighter coloured wires, they used white ink rather than black, so it is a bit harder to read, but overall is a great product that is well presented :)

  • A very useful sensor to measure enough precise temperatures of fluids.
    I measured three key points for use. Temperatures are in celsius. Why measure? To have better feeling and wider scale.

    -24’c = 33k ohms
    24’c = 2.78k ohms
    100’c = 178 ohms

  • This kit has everything you need for the present and the future and you dont have to hack up your factory wiring harness. Customer service is fantastic and support seems abundant plus you cant get a better unit for the money. And the packaging looks quite nice too! Extremely satisfied so far and I dont expect any disappointments. Would recommend to anyone.

  • Todos los productos megasquirt son totalmente adaptables y flexibles, en si no hay una recomendacion, debes de seleccionar tu producto de acuerdo a tus necesidades y metas, en la pagina de msextra, esta el contenido de como adaptar tu megasquirt a las caracteristicas de ignicion y alimentacion de combustible de tu auto.

  • Great tool. Don’t even think of using Weather Pack connectors without this one! I tried several alternatives and even bought a (fiber optic) die set for my Paladin 1300 crimper that would crimp the seal end. Unfortunately, all attempts to use it failed. All other crimpers I tried either didn’t crimp the seal on correctly or flattened little tabs that keep the connector from going too far into the housing. This guy crimps where the connector needs to be crimped, and doesn’t flatten or bend anything that doesn’t need to be flattened or crimped.




  • Perdon, no vi que querias swapear un LS1, a mi punto de vista si vas a hacer todos los arreglos para distributor less, no tiene caso usar tu TBI es mejor usar el intake del LS1.

  • quiero meter un ls1 a mi camaro modelo 88, que nesesito para poder meter el sistema tbi ya que el ls1 no cuenta con distribuidor? que polea necesito y que sensor?

    I put a ls1 camaro my Model 88, I need to put the tbi system since the ls1 does not have a distributor? trigger wheel and sensor?

  • Watch the pins on this guy. During assembly process I removed the chip board per the asm manual and broke two pins. Not real happy about it – very expensive mistake. I have removed other eproms for rechipped engine and trans ECUs and this is the first time one has broken on me. When seated it is very well secured but if you have to remove it be very very careful. When if finally broke loose the last two pins broke at the opposite end I was prying on. Fortunately the pins did not break off in the eprom reciever. It could be worse but again, not real happy about this.

  • super fast shipping, installed painlessly (win7 literally was plug n play) also it does NOT need the DB9 straight though serial cable to use it (I had a USB to Serial adapter that did require it)… so nice bonus.

  • Does not include the most important part…The connector! Buyer BeWare This is ONLY the cover. Quality seems high but kit is WORTHLESS with out the actual DB37 Connector. Make sure that you know what you are buying here, the term -with Hardware- is a bit misleading (in my opinion). In this description -with Hardware- refers to the tiny little screws that hold the clam shell together, parts that should be included regardless.

    (Comments from DIY)
    It is true this does not come with a DB37 connector, but then again, the listing pretty clearly shows exactly what it does come with both in image and in text. Not sure how we could have made that clearer. Our ECU kits come with the connector and a plastic hood (that works fine), this is offered primarily as an upgrade to that for those that want a heavy metal hood instead.

  • Once again….Incredible product and amazing shipping. arrived way before I expected it, everything was packaged well and well labelled. As usual after a few hours at the worktable I was up and running. the JimStim works even better the the older one I had and leaves room for lots of upgrades.

  • Absolutely wonderful product that is very fun to play with. Besides that it has so many useful purposes when diagnosing ECM and sensors. Don’t know how I worked without it.

    Add to that the wonderful sales and tech support from DIY Auto Tune and it’s a win win!

  • Great product! It certainly does make it much easier to connect your MS to ANY computer and not just old serial-port equipped computers. The other option is a small selection of finicky USB-Serial converters.

    I use this on my MSII with my MacBook while running TunerStudio and I could not be happier. Fairly simple to install and the DIYAutotune is/was top notch. G2G

  • Great service, fast delivery over the sea to the Europe !

    Had a few problems to start with as it needed the usb to be plugged in for MS2 to power on
    but thanks to matt i sorted it with a transistor mod

    cheers and thanks


  • I should not have to tell you that the more protection one builds into a MSECU system the less one has to worry about with errant voltage spikes hitting the ECU board – doesn’t matter if you’re using the MS-I or MS-II and the multitude of circuit board versions and software available to the system. Go for it – it is a lot cheaper than the equivalent Painless Wiring relay control system.

  • I have installed one of these cannon plug connectors in my VW Bug (yes, you read it correctly a 1969 Bug with FI and Turbo (300 hp engine)). It makes removing the engine for maintenance and further modifications a snap. I have, also, included quick disconnects for my fuel and fuel return lines between the chasis and the engine. I have been an engine builder (Chevie SB, Ford SB, and air cooled Corvair and VW high performance engines) since 1969. I have learned that the more thought one puts into a major build project the greater dividends it pays in the end. When I bought my MS-II v. 3 kit, I thought long and hard with the installation process and what would facilitate easier maintenance – THIS PRODUCT MAKES A WORLD OF DIFFERENCE WITH USING A MS SYSTEM IN ANY VEHICLE. I recommend that you consider this whether you’re using a stock or custom wiring harness. Since I’m doing a total build to include the normal electrical system and numerous aux engine gauges, I intend to buy a second connector kit to better separate and incorporate non-ECU connections.

  • Very nice. I am running mt Megasquirt II in a sandrail, so everything is pretty much a custom setup. I only needed about 2 feet of wire to run to the motor, and the labeling is nice, this way, if I have a problem at the dunes, it will be easier to trace my wires.

  • Excellent kit, great website. I will be ordering anything else I need from these guys here. First time putting things on a PCB, easy to follow along what needed to be where.