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Megasquirt: Q&A

13K views 8 replies 8 participants last post by  kenepo_tacoturbo 
#1 ·
Hi all I have been getting more and more questions about Megasquirt lately. So I am going to create a thread to help everyone out and answer some generic questions.

My background on this I have been running Megasquirt since 2006. I have a pretty good understanding of it and what it takes to install and run most engines. Right now I currently run Megasquirt 2 v3.57, 2.1.0d Extra code, and EDIS 6 for ignition control. This is installed on my 1990 toyota supra with a 1JZ.

Go here for you basic questions about Megasquirt that is not specific towards the supra and M/JZ series motors. I'll be going for more a specific questions aimed towards Supras.
http://www.bgsoflex.com/megasquirt.html

Guess I can start with some Q&A here

Q: How hard is Megasquirt to install on XM/JZ motor and is their a PnP version available?

A: How hard something to install depends on anyone's knowledge and technical expertise. Now I am not going to say anyone can do but with reading and research I believe any person with the right skill set and patients can install it. I started out knowing nothing about MS or standalones when I started and with no one around to help me just the MS forums and manuals. Now www.diyautotune.com builds a DIY PnP MS2 for the 7M engine but it is not Plug and Play you still have to do some soldering and research to get it running.

Q: Can I use all the stock sensors with the MS2?

A: Yes and no on this question. You can use all the stock sensors with certain modifications done to the MS2 it self such as to read the 7Ms stock CPS. On the JZ series of motors the MS will not work with the stock ignitor so you have to find another solution for ignition control.

Q: Can I pay someone to install and tune the MS for me?

A: Now there is some people that do MS installs but not that many because the MS was originally developed for the do it yourselfer. Typically people who do MS is for people who don't want to spend a whole lot of money or like to do things for themselves.

Q: How does MS compare to other standalones out there?

A: Now I can't answer this question completely because I haven't used anything else but MS. For the money you can't beat it but it does have its drawbacks of if you run into issues you may not have anyone local to help you solve your problems.



This should be good for now If anyone has a question or any helpful information please ask or add to it! I'll add any good questions with answers to the thread that come up.

IGNITION SECTION:

Alright here I'll explain prolly the easier ways of doing ignition on the 7m and then on the 1JZ/2JZ.

Ok the 7m ignition system uses and dual trigger 24-tooth/ 1 tooth trigger setup which is known for causing issues due to brittle wire. Then there is the ignition module which drives the three coils in a wasted spark configuration of cylinders 1-6, 3-4, 2-5. Now it is possible to run the stock 7m ignition system but with some electrical mods done to the MS unit itself which maybe be easy for some and not others.

Alright one way is to do the mods to the MS ecu and run the stock ignition system which is going to be hard for most people.

Now the one I recommend is using EDIS-6 from a ford mid 90's V6. Now the MS2 ECUs from Diyautotune.com already come setup for EDIS use. EDIS is very reliable ignition system to use and is pretty easy to get a hold of the components required to install it from most junk yards. It will also fire the stock coil packs and IS300 coil packs. There is some wiring that has to be done to install it. The hardest part of the install is installing the 36-1 trigger wheel and VR sensor on the crank pulley. The nice thing about using a crank trigger is you can get rid of the stock CPS and plug the hole with a freeze plug. Only drawback is controls such as 2-step launch won't work. Things needed for this install is below.

VR sensor
EDIS-6 Modules + pigtail
36-1 trigger wheel mounted to the crank pulley

Next would be modifying the stock CPS to a 24-1 trigger wheel as linked below. Now what you can do here is using the stock CPS modified to the 24-1 trigger wheel and drive Bosch ignitors or a Mitsubishi v6 ignitors. I haven't done this type of install yet but it is supported by MS2 and from what I heard works well. This wouldn't be a real hard task to do since it will require some wiring to do also.

I'll do the 1JZ/2JZ section later.

WIRING SECTION:

Now you can use the stock wiring harness which I don't recommend. I would use the Megasquirt 12' labeled wiring harness and do a custom harness which looks really nice and isn't hard to do if you can strip and connect wires.

I'll add more later.

FUEL SECTION:

The 7m electronic fuel system is a semi sequential fueling which fires injectors 1-6, 3-4, 2-5 as same as a waste spark setup. MS2 out of the box supports only batch firing which would allow you to fire two banks of injectors instead of three like the stock supra ecu does. Now you may think this is a down grade but really isn't batch firing works just fine its all in the tune.




Here is a write-up a friend of mine did to modify the stock CPS to a 24-1 missing tooth wheel MS can easily read.
http://www.saturnwiki.net/index.php/Nippon_Denso_CAS
 
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#4 ·
#6 ·
i run the diypnp on my 2jzge (na-t), and if anyone is looking to run this on their a70 supra i'd run a ms2 or a ms3 not the diypnp.
 
#7 ·
Interesting. I plan on running MS3X on my 7MGTE when the time comes. Here's an E-mail I got from Matt Cramer at DIYAutoTune.com. It may help.

Hello Alvin,

Here's the basics of what you'd need to run the engine. The 7MGTE ignition module is a bit of an oddity that the current firmware does not support, so that is a minor complication. This is a list of parts I would recommend.

- MS3 with MS3X
- Main board harness and MS3X harness
- JimStim test board (optional - simulates signals from a running engine so you can test the ECU on a bench)
- 3 channel Ignition module (or coil on plug coils with built in ignition modules) - I'd probably use an off the shelf Bosch one if you're in Europe
- USB or serial cable to connect the MS3 to a laptop
- GM IAT sensor (optional, but it makes removing the vane air flow meter easier)
- Wideband sensor with controller (optional, but makes tuning a lot easier)

We had a temporary delay getting some parts in, but a complete MS3 should be ready to ship in just a few days. The kits are ready for immediate shipping. It's likely to take around 8-12 hours to solder a V3.0 kit together if you go that route. The directions can be found on MS3EFI.com in the Documentation section.

Thanks,

Matt Cramer
DIYAutoTune.com
 
#8 ·
matt is a cool guy. he has helped me a lot with my diypnp. i dont really have a problem with the ems itself, its just nowhere near pnp for the mk3 supra. plus it cant drive the 7mgte low impedance injectors, maybe with certain resistors that's a different story. it also can't work with the 7mgte ignitor, which a lot of the wires on the 7mgte harness are daisy chained together. so, eliminating the wiring for a key engine system and not having it effect the other engine functions/wires/sensors is next to impossible. but it does have a lot of cool features, and its way easier than the ms2 to assemble (i've built both). i really like the ms2 for how cheap it is and how well it works. if you get that with the optional direct coil control (the bosch 373 transistors i think) it can pretty much run off of whatever signal you can get to it. plus it can do just about everything you would want (if you get the proper upgrades). as for the ms3 boards, it looks just like a more advanced ms2, and there's absolutely nothing wrong with that =)
 
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