MegaSquirt II Successfully Running on 7M-GTE!!! (Lots of pics and walkthrough)

87_7MGTE

SOLD :(
Mar 30, 2005
278
0
16
Bellingham, WA
Right away, Pictures Here: http://www.freewebs.com/supraboost/gallery/megasquirt.htm

Sorry for the long post, but I figured people might want to know how to do this!

Well, I did it! I got a Megasquirt II v3.0 running on my car with EDIS-6 ignition. The project wasn’t all that hard, just time consuming. Things to note:

• Full standalone, fully configurable
• Datalogging
• I used EDIS-6 ignition, so I could retain the stock coil packs (and I can go COP later on)
• I bought a unassembled MSII v3.0 kit, relay board and stimulator board
• I made my own wiring harness from scratch (with plugs from an old 89 NA harness, so that my harness would plug directly into my injectors, etc.
• Etc., Etc., ETC.!!

Supplies that I ended up needing:

• MSII unassembled kit
• Relay board (what all the I/O signals go through. Main, Idle Valve, and Fuel Pump relays are also on this)
• Stimulator board (used for bench testing)
• EDIS-6 ignition module, VR sensor, and trigger wheel
• 1 GM Intake Air Temp Sensor
• 1 GM Coolant Temp Sensor
• 1 GM 3-BAR map sensor (the kit comes with one, but its only rated to ~20 psi)
• Wideband O2 (I went with Zeitronix, essential for tuning and autotune, plus its just good to have!)
• A TON of wire (I bought ~900 ft of wire, all different colors)
• Misc. Vac lines
• Misc. Vac plugs
• A few GM Weather-Pack Connectors
• Shrink wrap of various sizes (mostly 1/8”)
• Wire loom of various sizes (mostly ¼”, and ¾” to 1” for main harness)

Optional, but you will almost definitely need:
• Electric cooling fans (unless you make the VR sensor bracket different than we did, the bracket sticks out too far to retain the clutch fan)
• From an old harness or the harness you are replacing, the TPS, injector, oil pressure sensor, ABS, reverse lights, PPS, coil pack, and water temp gauge connectors (for easier wiring)
• Pre-89 Throttle Body – I used this to get good idle speed, but there may be another way with tuning (timing advance, some sort of ISC or FIdle Valve, etc.)


It’s an absolute MUST that you have a laptop for tuning!

It’s real straight forward on what to do. After soldering the ECU, Relay board, and Stim together (I would recommend building the Stim and Relay board first, the ECU is a little more overwhelming), I took out my stock ECU and wiring harness, and started making the new one, cutting the wire PLENTY long. The only stock things that need to be connected are the injectors and the TPS. Make sure you wire in the TPS the right way, or else you will get backwards readings. See the TSRM and TEWD on how to do this, along with the Assembly Guide. But anyway, making the harness is really quite easy; it just takes a long time. I took the TPS, injector, oil pressure sensor, ABS, reverse lights, PPS, coil pack, and water temp gauge connectors from an old 89 NA harness and soldered them where they needed to be respectively. I also used the M1 and B1 connectors shown here so that I could have heater control and connect all my stock gauges up. All the gauges (water temp, tach, oil pressure) connect to the M1 connector, and the heat and clutch start switch connect to B1. Also, I batch fired the injectors 1, 3, 5 and 2, 4, 6, it works really well. After all the wires have been cut for the harness, I shrink wrapped and loomed the whole thing for a good, clean, and OEM look. Leave the ends out though so you can cut them and connect them to the Relay Board. Once that’s all done, you need to make a harness that goes from the Relay Board to the Megasquirt ECU (Instructions here). My Relay Board is between the shock tower and fender on the passenger side, and the ECU is under the passenger’s seat, because for some reason, I couldn’t get it to fit under the dash/glove box with the ABS computer there. Also, bring the 0-5V connection from your WB to the O2 socket on the relay board. Ok, yay, all wired, except for main 12V, ground, and switched 12V. I made another small harness that went from the Relay Board to the battery, and pulled switched 12V from my turbo timer harness.

Next, ignition. (How to wire it here). Get rid of the stock ignitor. The EDIS-6 ignition module fits almost perfect where the stock one went. Then I connected the coil packs to the EDIS-6 module (packs 1, 2, 3 are A, B, C respectively). Then I connected the IDM wire (pin 2) to my stock tach. Next, ground, then switched 12V to the module, and 1 of the pins on the coil packs, with a capacitor in there to filter noise (look at the wiring diagrams, link above). After that, we made a bracket to mount the VR sensor on, so it could pick up the signal from the trigger wheel mounted on the crank pulley. You have to make this bracket first! The sensor is dependent on where the missing tooth is on the trigger wheel, not to TDC (well it is, but simply put...). We made the bracket to mount to the A/C tensioner pulley. This takes a lot of trial and error, getting it in the right place and to line up exactly with the trigger wheel. Lastly, we had to weld the EDIS trigger wheel to the crank pulley and balance it perfectly. The missing tooth has to come 6 teeth before the sensor sees it. I know, it sounds complicated, and it sorta is, but if you read the forums and just get into it, you will understand it.

After everything is wired, I drilled a hole in my hard pipes right before the throttle body, tapped it, and put the IAT sensor in it. I put the coolant sensor in where the VSV used to be in the water neck. Then I took out the horn on the firewall and put the MAP sensor in its place (because I’m getting an aftermarket alarm).

Well, by now, everything is basically wired and installed; now it’s just time for tuning. There is plenty of info on the MegaSquirt site on how to tune it. All I did to make it start the first time was input the injector parameters, and it started (although hella rich).

Overall, I am really pleased with the results. It's a full standalone, and you can tune just about anything imaginable. It runs super smooth, and there is plenty of power, although I haven’t gotten into a lot of boost yet, I am still tuning the AFRs and ignition map. This isn’t for the faint of heart, it’s a definite project. And yes, I know the car needs a wash, it sat for ~3 months while I gathered the supplies and did this!

I wanna thank Alex for helping me with the project, welding, and dyno time, and my bro Jeff for all his hard work!

High res pics available upon request, and I will also be adding more pics in the next few days for the VR sensor bracket, where the ECU is mounted now (as opposed to under the dash as in the pics), and other stuff.

Comments and questions are welcome.

Good luck, and enjoy!



More info you WILL need:

http://www.megasquirt.info – The mother ship for MegaSquirt info.
http://www.msefi.com – MegaSquirt forums, A LOT of good info here.
http://www.not2fast.com/megasquirt - where you get the tuning software.
 

siman

Lifetime Ban
Mar 31, 2005
1,371
0
0
39
Murfreesboro, TN
www.cardomain.com
I was %99 sure I was going to embark on the MSII system 6 months ago...but that fizzled as I worked so much and had little time to tinker with the supra. Now just using a profec B spec II and SAFC II. I guess it will work :rofl:

I would still love to utilize it on my supra, I have a friend with 3 DSM's running with the MSII system, it consistantly sends his car (main) into the mid 10's in the quarter now!...its simply AMAZING!

It does just as much if not MORE than the AEM EMS or Greddy system and at HALF the cost!


great info I might add! way to go!

-Jonathan
 

87_7MGTE

SOLD :(
Mar 30, 2005
278
0
16
Bellingham, WA
GrimJack: I totally meant to say cost and hours. Everything you need (including wideband and EGT probe) was between $700-800. I put my car in our shop around thanksgiving, and got it running last weekend, but i only worked on it a few days during the week, so i would say it took about 40-48 hours for the whole project.

and also, EVERYTHING works!! or at least, i havent found anything that doesnt work yet, all gauges work, heat, defrost, radio, lights, etc.
 
Last edited:

87_7MGTE

SOLD :(
Mar 30, 2005
278
0
16
Bellingham, WA
nope, stock ECU is history, no need for it, MegaSquirt II is a full stand alone

ninja EDIT: also, IJ: thanks again for helping me with the ignition map!
 

87_7MGTE

SOLD :(
Mar 30, 2005
278
0
16
Bellingham, WA
IJ. said:
No probs at all!

I think the stock ECU runs the ECN setting of the Air Con I know I lost it when I went standalone.
i think you are right, but im going to try to find a way to get this back, im not sure how im going to do it though!
 

87_7MGTE

SOLD :(
Mar 30, 2005
278
0
16
Bellingham, WA
Reign_Maker said:
How much hp would you say you could go with on this set up?

it has just as much tunability (if not more) than aem, motec etc., etc. its just another EMS that not many on this forum have tried (if any)

so to answer your question, it depends on how well you can tune it. you could get whatever you want (with supporting mods)
 

Dirgle

Conjurer of Boost
Mar 30, 2005
1,632
0
36
42
Pauma Valley, CA
I'm glad to see you went this rout. I've been looking at the MegaSquirt for some time now. I like the hands on approach you receive. You get a good idea of how an ECU actually runs the motor plus I think it would be fun to tinker. Also it's a neat idea that you can write some of your own code to control the ECU. Since I like to dabble in programming every now and then I think this would be fun too.

Good work and keep us updated
 

87_7MGTE

SOLD :(
Mar 30, 2005
278
0
16
Bellingham, WA
Racefiend said:
Nice! One question though. Are you using the megasquirt to control the ISC valve?

no im not, at least not yet. i havent decided if im going to use the stock valve (highly unlikely at this point, as i dont want to modify the MSII board more), a fast idle valve, or a coolant controlled idle control valve
 

Racefiend

OH, YEAAHH!
Apr 6, 2005
106
0
0
47
Bay Area, CA
87_7MGTE said:
no im not, at least not yet. i havent decided if im going to use the stock valve (highly unlikely at this point, as i dont want to modify the MSII board more), a fast idle valve, or a coolant controlled idle control valve


I thought the v3 board with the ms2 was able to control a stepper motor? Why would it need any modification? (sorry if I'm a MS newb)
 

figgie

Supramania Contributor
Mar 30, 2005
5,225
16
38
50
Twin Cities, Minnesot-ah
87_7MGTE said:
no im not, at least not yet. i havent decided if im going to use the stock valve (highly unlikely at this point, as i dont want to modify the MSII board more), a fast idle valve, or a coolant controlled idle control valve

can the MS control a Chevy 4 wire Idle Air control valve? If so then the stock 7m ISC will work ;)
 

87_7MGTE

SOLD :(
Mar 30, 2005
278
0
16
Bellingham, WA
IJ said:
You could probably use the same Solenoid that I use if the ECU does PWM

yes, it does support PWM :)



Racefiend said:
I thought the v3 board with the ms2 was able to control a stepper motor? Why would it need any modification? (sorry if I'm a MS newb)

when you solder the MSII v3.0 board together, there are options you can solder in. For example, you can wire in either a Fast Idle Valve, PWM, or stepper style valve (our stock valve). You also have these options with ignition. You can have either Ford EDIS, GM HEI, direct coil control from the MSII ECU, and there are a few others. So it all depends how you wire it internally.

figgie said:
can the MS control a Chevy 4 wire Idle Air control valve? If so then the stock 7m ISC will work ;)

yes, it can, and i know the stock valve will work, the only reason im not going this route is because when i built the ECU, i didnt wire it internally to accept any type of ISC (but like i said, i will probably change this soon, or get a coolant controlled one).