ECU#: NS9501A ( PCB VERSION 1.2 )
UPDATE 02/21/2016
I noticed some confusion about the spark outputs A and B for some users, just wanted to confirm what member "carbonfibers14" noted....if you are using the newer revision 1.3 board that has 26 pins on the rear instead of the older 15 pin ver 1.2 board like i used in this writeup, you will have completely different outputs for your spark A and B output. On a 1.3+ board, spark A will be pin 17 and spark B will be pin 16...please wire appropriately!!
Also , with proper cooling i have ran these coils up to 18 psi, stock .44 gap with a gt2871r at 3.0ms dwell time without any spark blowout , random discharges or overheating....they are no match for ls coils, but they sure can get the job done!
Lastly , there are some who had issues with the coils overheating when they installed them the way that recommended, please make sure that you have them set to "going high/ inverted" IF they still overheat then try "going low" to see if that helps before changing the way they are wired ( Im not sure if this also is a ver 1.2 vs 1.3 mainboard difference OR perhaps i truly have them wired incorrectly in my diagram, unfortunately i am not able to check my wiring at this time , i sincerely apologize in the event that is in fact the case.
I'll start by saying that even though you realize how straight forward the installation is when you're done, there was actually a lot of trial and error in getting it to run without issues since documentation on running maxima coils is almost nil aside from people saying they have only 3 pins...power, ground and ecu signal. No one says WHICH pins those are exactly, what must be done with the stock ignition system to prevent interference, and also that not just ANY 12v ignition signal or ground can power them properly.
This guide assumes that you have the DIY aftermarket trigger wheel installed and timed correctly, as it is needed to run in wasted spark mode.
So... on to the coils, I chose the 01 maxima coils because they are drop in with perfect fitment, do not NEED a mounting system unless you feel like it, has a built in ignitor so no external one needed, they are triggered by 5v so perfect for us megasquirt users and best of all NO MORE PLUG WIRES!! Some folks use 95-99 maxima coils, which is fine, I just chose these because they are “newer” and felt a bit heavier, which in my mind equates to a larger coil..however I could be wrong, oh and don't forget...you need to use 4 coils from the FRONT BANK of the maxima. I bought mine new but If you go to a junker you need 2 donor cars.
To get things started, lets orient ourselves with the maxima coils, From top to bottom we will label the pins X, Y, and Z.
You will need to run 2 wires from your MS2PNP module to the coils.
1. PIN 2 of the ecu is SPARK “A” which needs to be ran to the coils on cylinder 1 and 4 ONLY by connecting them to PIN “Z” of both those coils. (this is the signal that charges and fires the coils)
2. PIN 3 of the ecu is SPARK “B” which needs to be ran to pin Z of the coils also, but ONLY on cylinders 2 and 3.
3. PIN 15 is an ecu ground, which is how I grounded all 4 of my coils at first, which proved not to be sufficient under cranking, therefore I highly recommend you DO NOT ground the coils at the ecu...instead you should ground the coils at the engine head or intake manifold.
4. SIDENOTE: I chose to run PIN 11 of the ecu to my aftermarket TACH as my tach signal did not work after this installation.
5. Powering the coils:
Now this can be one of the most overlooked, yet important parts of your installation, you need to power all 4 coils with an ACCESORY 12v power supply,however it must also be a power supply that is not affected by cranking otherwise the coils will not have enough juice to get your motor started (trust me). I chose to run a direct connection to the battery using an 80 amp battery isolator relay, 80 amps is probably overkill but its what I had laying around. I am triggering the relay using an “add a fuse” On the fuel pump fuse in the driver side fusebox ( s14 ). When the relay receives 12v it engages the heavy duty direct battery connection to all 4 coils.
Here is a basic overview of what I did so you can get a picture in your head of how to go about your install.... (DONT HATE ON MY PAINT SKILLS)
Now that the coils are completely wired up, its time to disable the stock ignition system so that it does not fire simultaneously as your maxima coils...if they do, they will cause serious interference and you will get erratic timing at higher rpms which will induce serious knock and possibly kill your engine. In order to do this simply disconnect the 2 pin connector on your distributor to kill the power to the coil. Don't touch the 6 pin connector on the distributor as that is what carries your CAS signal.
Now for the fun part, lets test everything to see if you did a good job, or if you just need to hand your 240 over to a more competent being...me......i kid I kid:-).
First lets configure megasquirt to run in wasted spark mode instead of using the stock single coil. Use these settings and you should be good to go, as you can see I'm using 1.3ms of dwell time and can currently hit 15lbs of boost without blow out on the stock plug gap for NGK bkr7e plugs. I recommend you start with 1.0ms which is considered a safe starting point for these coils (from what I read) and work slowly up if necessary checking for excessive heat build up on the coils. (trigger angle varies by motor, please use your own value here otherwise you will have incorrect base ignition timing)
Next up connect a spark plug to each coil and ground all 4 to any spot on the engine to test for spark.
lets start by:
1. Opening tuner studio with the ignition on and connected to the ecu.
2. Click on “Advanced”
3. Click on “Output Test Mode”
4. Enter the values you see below exactly as is then hit BURN and you should be getting spark from “COIL A” which are cylinders 1 and 4
5. Now select “COIL B” which are cylinders 2 and 3....you should now see spark from both of these.
Now that we have successfully wired up our coils and tested for spark..... its time to fire her up!
Install your plugs, connect the coils and let her rip.
Once you have her started you will want to verify timing by using the fixed advance table to 15* (or 20 or whatever number floats your boat) and verify that it holds that number ALL THE WAY to the maximum rpm that you use....you need to do this to make sure that the timing is not drifting in the upper rpm range.
If you have done all these things correctly, give yourself a pat on the back, a cold beer and enjoy your new distributorless COP ignition system!!
