ms3x how to guide for 7mgte

jdmfreak

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#1
This writeup is how I built and installed ms3x in my 90 supra with
full sequential ,launch control , boost control , using stock cps if you choose to follow this writeup you do so at your own risk:)
i wish you the best of luck


first I would like to send special thanks to pyro15d, Nathaninwa, and terrencelp you guys were excellent help getting me going
and i would like to thank BryanDyer, 3tc power, and suprajztwenty for assisting me with this writeup


OK,the ecu,
I chose the unassembled ms3 from diyautotune

here are the diy part numbers for all the items I needed

[MS330-K_m4]
*MS330-K kit with MapDaddy4 Upgrade*
(mapdaddy 4 is a 4 bar map sensor that allows for real time barometric correction)
this is the case, base unassembled ms3 ,and map sensor


[MS3Xpander]
*MegaSquirt-III MS3X Expansion Card*
This is the extra card required for full sequential fuel and ignition as well as launch control and a bunch of other goodies



[MS3Knock-K]
*MS3 Knock Module Kit*
This is the knock module you need if you are planning on running knock sensors




[MS3TuneCable]
*USB cable for MegaSquirt-III*
Tuning cable



[MS3X-Harness]
*12' MegaSquirt Wiring Harness for MS3X*

[MSHarness12]
*12' MegaSquirt Wiring Harness (MS1 / MS2 / MS3 Ready)*
(note you do need both of these harnesses)I got these harnesses however they also have 8' harnesses that also work and will need to be trimmed (for both the 12' and the 8' harnesses you will need to purchase extra shielded wire for your knock sensors and the cam input as they do not come from diy shielded


[EBC_Sol_kit]
*EBC Electronic Boost Control Solenoid Kit*



[IATwPiggy]
*GM Open Element IAT Sensor with Pigtail*


[38NPT-Bung_A]
*3/8" NPT Aluminum Weld-On Bung for IAT or CLT Sensor*

I did not use the jimstim, at this point it does not simulate our cps but will help if you run into any problems when you solder your own board together


for my build I used ls2 coils, however, these would not work as well with a stock intake manifold, in that case 1zz coils will work fine




I also am using high impedence fuel injectors so I dont use a resistor pack if you are using low impedence injectors you will need to use a resistor pack suprajztwenty has a great description in post #6 in this thread



purchase tunerstudio and megalog viewer its worth it



BOARD ASSEMBLY
http://www.msextra.com/doc/ms3/build_manual.html

as there are different jumpers to install or remove keep in mind if you will be using the stock cps to follow the instructions for VR sensors
and if you are using the stock iacv it will be a 4 wire stepper motor(stock it has 6 wires we will only be using 4 details in the wiring section)

for trigger input use V3.0 VR input (for VR)



on ms3x this is taken from the ms3x website
JP7 is a jumper for a pullup on the "Cam" input. This is typically required with hall or optical sensor inputs. It should NOT be used with VR sensor inputs.*
When using hall or optical sensors inputs, the cam input adjustment potentiometers should be set as follows. Turn both pots (R11 and R32) full anti-clockwise - approx five turns. Then turn the top one (R11) two turns clockwise.*
When using a VR (magnetic) sensor input, the cam input adjustment potentiometers should be set as follows. Turn both pots (R11 and R32) full anti-clockwise - approx five turns. This is usually the right setting.


WIRING

I started by separating my harnesses into (to dash) and (to engine bay)


ENGINE BAY HARNESS (38wires)
all grounds /sensor return(11 wires)
6 spark output wires a-f = LS2 COILS (wire all spark outputs in firing order aka a=1 b=5 c=3 d=6 e=2 f=4)
6 injector outputs a-f =ID 1000CC INJECTORS(high z)(wire all injector outputs in firing order aka a=1 b=5 c=3 d=6 e=2 f=4)
coolant temp=COOLANT TEMP SENSOR(this is a signal wire use sensor ground b/w wire in ms harness for ground)
boost control=EBC(this is a ground wire other side of ebc needs switched 12v)
spr3 (knock input)=KNOCK SENSOR 1(replace with shielded wire)
spr4 (knock input)=KNOCK SENSOR 2(replace with shielded wire)
cam input=CAM POSITION SENSOR(replace with shielded wire)goes to yellow wire on cas
tps sig=TPS(vta stock wire is W/R)
air temp=IAT(this is a signal wire use sensor ground b/w wire in ms harness for ground)
crank sensor=CRANK POSITION Sensor goes to red wire on cas(the other wire in the shielded pair is the ground for both cam and crank sensors and should be attached to the white wire on the cps)

+5v vref=TPS(vcc stock wire is L/R)
12v+ switched=needs to tie into a wire thats going from small gauge b/o in connector (C1) to the small gauge b/o WIRE in connector (B1)*
vvt= i used this to signal my ELECTRIC FAN RELAY
iac1a=w/y wire in cps
iac1b=L/R in cps
iac2a=R/B in cps
iac2b=G/W in cps

the black wire with a white stripe is the sensor ground and needs to go to the ecu coolant temp sensor,the iat sensor and the e2(brown)wire on the tps(note the tps has a 4th wire this is the idl (Y/L)wire and will not be used with the ms)

a couple of the black ground wires need to be used for "signal grounds" on the coil packs
all other grounds need to be grounded to the head preferably in the stock location on the intake manifold

DASH HARNESS (or currently unused)(27 wires)
tach output=BLACK WIRE in the (M1) connector
o2sig=WIDEBAND O2 SIGNAL (from your wideband o2)
datalog input=BUTTON ON DASH for datalogging with sd card button needs to be temporary push connected to ground
spr1=UNUSED
spr2=UNUSED
nitrus input=UNUSED
nitrus out=UNUSED
nitrus out 1=UNUSED
spk g+h=UNUSED
inj g+h=UNUSED
fuel pump relay=GREEN WIRE in (B1) connector
pt4 logic output=UNUSED
ext_map=UNUSED
inj bank 1(2wires)=UNUSED
inj bank 2(2wires)=UNUSED
tableswitch in=SWITCH ON DASH* (on off switch connected to ground i use this to switch boost tables but can also be used a variety of different ways
idle valve=UNUSED
pwm idle=UNUSED
flex fuel input=UNUSED
ego2=UNUSED
launch cntrl= tap this wire into the CLUTCH SAFETY SWITCH (make sure you hook this to the side of the switch that only gets grounded when clutch is depressed)
spare adc=UNUSED
spark a (from ms3 connector)=UNUSED




Then add additional wires to the engine bay for the following

2wires for pps(if equipped) these go from the steering box to the (B3) connector
1 large gauge wire branched to power coils and injectors from large gauge b/o wire in connector b1
3 wires for rear abs speed sensor(if equipped) (from rss to (B3) connector)
1 wire for starter activation (to starter from b/l wire in (B1) connector(or if automatic from neutral start switch)
1 wire for coolant temp to stock gauge (y/g in (m1) connector)
1 wire for oil pressure stock gauge (y/b in (m1 connector)
2 wires from c1 to b1 (one is a small gauge b/o wire for mrel which i have already mentioned under 12v+switched) the other gives power to the fp relay and is a b/r wire
2 wires for backup lights from backup light switch in trans to wires y and r/b in the (M1) connector

the cps is the hardest part to get dialed in,

there are a few key points to getting the cps dialed in,
1 every cps i have come across so far (close to 10 off the top of my head do not match the wiring diagrams i have found
so use these,
red is ne(or crank signal coming from the 24 tooth wheel)
yellow is g1(or cam signal coning from the single tooth wheel) using this pickup will mean your tooth 1 angle will be really close to(if not) 20
white is ground(all three sensors in the cps have their grounds tied together inside the cps it is ok to leave it this way
(do not use the green wire)




to clear up the signal you will most likely need to regap the sensors,(I WOULD HIGHLY SUGGEST PULLING THE CPS OUT FOR THIS PART AND SPINNING BY HAND AFTER GAPPING TO ENSURE THAT NONE OF THE TEETH COME IN CONTACT WITH THE SENSORS) take the sensor you are using for the cam signal and the sensor on the 24 tooth wheel and gap them tighter than stock(i used a $20 bill but take caution as i know a guy who snapped a tooth off his cps by gapping it too tight and he also used a $20 bill)
then take the sensor you arent using and gap it as wide as possible to reduce possible crosstalk between sensors


in the ms3x manual here
http://www.msextra.com/doc/ms3/ignition.html
and in the build manual it says turn the 4pots(2on main board and 2 on ms3x board) fully ccw to set them up for most vr sensors
however from what i have seen the best signal is around 6 turns clockwise on the 2 mainboard pots and slightly cw on the ms3x board but this is something you will have to play around with along with the composite logger in ts to dial in for your car


here is a page that i hope will be running soon to help with this http://www.msextra.com/doc/ms3/vrpots.html




STOP!!! BEFORE YOU START YOUR CAR READ THIS AND FOLLOW THE INSTRUCTIONS!!!!!
http://www.msextra.com/doc/ms3/firststart.html




EXTRA PICS:)













please ask if you need any clarifications
 
Last edited:

jdmfreak

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#3
Thanks Bryan, I'll get to that tonight I have some more pictures and I'm going to continue with labeling all the pictures and putting them in order, next section will get into what grounds where, setup instructions and whatnot
 

suprajztwenty

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#6
^^^^first thing, i have to say this dude is awesome!!! i built my board and wired up myself but seriously 90%+ of the rest i owe to him.

"Then add additional wires to the engine bay for the following"
please add a/c clutch to this list...if applicable

heres my contribution, best body plug pinouts ive found one






for clarification, b1 is the first plug pictured, c1 is pictured here (right next to fuse box under hood)


if you build your own board, this is a must! anything in a pink bag (and any time after installing anything from a pink bag, you should wear one of these any time you touch the board. its an anti-static band. make sure the opposite end is well grounded (litterally, on the ground/floor) i wore mine on my ankle the whole project.


id like to elaborate on the OPEN ELEMENT intake air temp sensor. its open element in order for it to read faster. i settled on deleting my cold start, fabbing a plate and mounting it like so. just make sure its in a good airflow area if you dont choose the same place. also note i havnt completely deleted the cold start, i just have it hanging off the rail until i get a plug for the stock rail


low reistance/stock injectors...acura legend v6 injector resistor pack (i chose to mount mine to the driver side motor mount (engine side bracket to be specific...and square mounts) legend's are the square medium body cars. this pack is found directly under the fuse panel under the hood, you cant miss it. simply wire a switched 12v supply to the yellow wire, then take each red feed up to the injectors. i kept the stock connector pigtail for simplicity.


gm lq9/ls coils are the way to go because you can delete the stock ignitor and control the coils directly from the megasquirt (no extra ignitor/modules needed). (lq9's are a variant of ls coils but have a heatsink built into them...from what i got out of it, better for tuning dwell=stronger spark...still a little over my head but yeah...) search up lq9 COP, i think 2j guys have been doing this mod for awhile now.
i did mine an ass backwards way, i mounted this setup on the exhaust side valve cover...shouldve just done coil over plug but i had this plate laying around in my toolbox and decided to make it work. staggered so the stock 3k pipe can route between. i had to drill a large'ish hole in front of the #4 coil pack so it can slide over the crank vent nipple. please dont copy me on this, i also had to delete the stock throttle linkage, route the cable under the intake, up through the runner and welded on a custom throttle wheel to connect it...it works but its seriously only temporary, it needs to go away.


as for wiring loom, i chose to go the expensive route and went with braided loom. also, i chose to only do the 8ft harness' (you need a harness for main board AND the expansion board) i had plenty of wire left to play with...8ft should do it if youre planning on mounting the box in or near the glovebox. i branched each sets out prior to loom. separated injectors, then spark, then SHIELDED knock wires(to keep from add'l signal interference), then tps and intake air temp, idle air and fan control, cam+crank shielded wire and coolant temp wires. i ran it all through the stock gromet (dont try and re-use the stock gromet unless you just have a stock harness you were about to throw away)


best advice i can give regarding megasquirt, TAKE YOUR TIME and triple/quadruple check! i got away without buying the jimstim stimulator but im pretty decent at soldering.
 

suprajztwenty

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#11
Ah, well I'll have an extra wire to fiddle with then, lol. So pin 12 on b1 connector is the stock input for idle up I'm assuming?
 

jdmfreak

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#17
for anyone considering megasquirting their car we now have a support group via facebook messenger:) we have 7m, 1j,2jz vvti and 1uz vvti guys in the group and we are usually available 24/7
 

kmfdmk

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#19
for anyone considering megasquirting their car we now have a support group via facebook messenger:) we have 7m, 1j,2jz vvti and 1uz vvti guys in the group and we are usually available 24/7
I'm not trying to troll here, but are you serious? I'm in the process of MS3X'ing (w/ RTC & Knock boards) my 7MGTE and doing the harness from scratch. I think I've got it mostly under control. I've got my pinout lists made up and all the supplies. I'm measuring my runs now and making up a wiring board next.
 

Bmettie

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#20
for anyone considering megasquirting their car we now have a support group via facebook messenger:) we have 7m, 1j,2jz vvti and 1uz vvti guys in the group and we are usually available 24/7
I'm not trying to troll here, but are you serious? I'm in the process of MS3X'ing (w/ RTC & Knock boards) my 7MGTE and doing the harness from scratch. I think I've got it mostly under control. I've got my pinout lists made up and all the supplies. I'm measuring my runs now and making up a wiring board next.
I doubt he was speaking to you directly, a year and a half ago.