Installing my megasquirt

[hgallegos915]

So I will be installing it from shadowme's 6th bulk buy. I just have a few questions and maybe simple to you .

What "Cut wire at ECU, splice to Injector." So I cut the wire that goes straight to ecu and leave nothing there? and then run that wire to the injector? or cut wire and leave it connected to ecu but at the same time to the injectors?


ALso what is the benefit of using the stock ecu with megasquirt and using megasquirt as standalone as it has two options?

Tap to ECU harness means that I make a cut and solder the wire to it right?

I need help 8nderstanding this.. so it wants me to CUT aka SNIP? My wires? When I am done the ECU will not have the wires going to it?(if i keep ecu)


1.10. Fuel Injectors
Installation: You have to snip all six Fuel Injector wires going to your factory ECU regardless of whether or not you are keeping the ECU. What you want to do is join them into TWO groups; one front bank cylinder with two rear bank cylinders in group ONE, then the remaining three cylinders in group TWO. Be sure you strip the wire back far, 1” or more, and carefully join al three wires in each group because it is critical you get a good connection here. I solder all my fuel injector wires to make sure the connections are good, then shrink-wrap or seal them with electrical tape. A missing injector can cost you a piston!! How the injectors work is simple: Each injector has two wires: one is 12v power directly from the ignition relay/battery: the other is the wire that goes into Megasquirt, it is activated when Megasquirt switches the wire to GROUND. Basically, Megasquirt is turning on and off the ground circuit to the injectors rapidly, and each time an injector is grounded it fires until it is ungrounded. It is critical not to have shorted wires, etc and a good idea to test each injector wire out at the fuel injectors for continuity into the Megasquirt wiring harness, using a voltmeter.


Injector Bank 1 Red 11, 12, 13 (C246) Cut wire at ECU, splice to Injector.

Injector Bank 2 Black 24, 25, 26 (C246) Cut wire at ECU, splice to Injector.

[marcdh]

Benefits... hmm not a massive lot IMO. Do you use air con? Piggyback if you do. You'll also lose idle air control going standalone, unless you bother to sort it out. I started piggy back then went standalone, it was just tidier and easier to wire tuck.

Ok cut the injector wires at the ecu (well a few inches back so you could revert if you needed to). I used 6 pin connectors at first so I could easily return the wiring to the standard ecu. So now you have 6 wires. You need to group them into 2 sets as described. So now you have 2 sets of 3 wires. Each set of 3 is soldered into one of the injector output wires of the MS harness. If it's the same as mine then it's the grey sheathed wire with a red and black wire inside. They're thicker than the rest of them. This mean your stock ECU should now have no connections to the injectors, otherwise MS and ECU would be sending signals!
So the path is MEGASQUIRT>BLACK & RED WIRES>STOCK HARNESS WIRES>ENGINE BAY>INJECTORS

[hgallegos915]

Sweeeeeeet! Thats just what I was looking for. I was confused as to why there are two sets of red and black but like you mentioned these are in a gray sleeve so those go to injectors. Awesome! Thanks!

I dont have an ac but it seems that for starters, piggyback seems the easier route.

[marcdh]

No problem, good luck with the install! Let me know if you have anymore problems and I'll do my best to help

[WhiteFinish]

That is correct.

Also don't forget to cut the disti wire towards the ECU.

I've created a table in Excel that will indicate wiring to the ecu from a standard Pre facelift v6 Mx3.
You can PB me your email and I'll share it. (or if somebody knows how I can share it online i'll post it there)?

[hgallegos915]

Ok so disregard the last spam..

anyways ok I am close. Now the MS instructions call the ECU pin outs by NUMBER. Example PIN1 is black and goes to ground.

Yet on the ECU the pin outs are labeled 1U 1s 1q and so on. Not in a numerical order. any tips?

[hgallegos915]

I get it!! So last question I PROMISE. I think..

TAP into ecu means get the wire cut into it and join a wire to megasquirt while staying on the ecu at same time?

[WhiteFinish]

Correct.

[mazda915]

hows it coming along hec

[hgallegos915]

Guys I need some final help as far as wiring goes. Its all done except two wires.


PINK which is for launch control. It reads "Wire to clutch pedal. Ground to activate"

Switchable tables reads "Ground to activate"


Almost there!

[marcdh]

You don't need switchable tables unless you're running n2o

Launch control you tap into the switch above the clutch pedal. It took a bit of experimenting to get the right one for me.

[WhiteFinish]

Did the table I've send help you ?

[hgallegos915]

Install was a failure, reverted back to stock wiring. Check my post in the v6 tech section for weak spark.