Electrical help with coils

[NICO]

set up is:

ej22t block, ej20g heads, ej20k intake manifold.
16g evo 3, sti 550cc injectors, fmic, equl headers.
autronic plug play ecu

the car is a gc8!! but it really is a 1991 legacy turbo.

what i want to do:

swap the coil pack to sti or wrx factory coil on plugs.

the good news is autronic, i can just switch what i want in the ecu.

the bad news is how do i wire it up with the sti or wrx coils in a 91 legacy turbo??

1991 legacy turbo ecu factory book dig


autronic settings for extra idea if there is a easy way on my car.


what should i do and where do i start?

some pepole would say why change, really i think i can pump out another 20wtq out my basic motor hands down.

[NICO]

there must be someone that knows how to do this swap??

[Legacy777]

You're going to have to run two leads from the autronic to two of the coils you install. You will have to re-wire the existing two leads to the other two coils, and then setup the autronic for individual coil setup.

[NICO]

You're going to have to run two leads from the autronic to two of the coils you install. You will have to re-wire the existing two leads to the other two coils, and then setup the autronic for individual coil setup.

sorry i just seen your reply now.

ok take it slow, let me see if i have this right

bye looking at the pins on the ecu plugs i take the two wires i have pin numbers F47. 9, F47. 10, then i add two wires in empty spot F47.8, F47.7, run all four wires to the cop, then change the settings in the autronic to???

also how do i know what ecu pin takes what cyc #??


i hope this is worth it, i can make more power right?

[93forestpearl]

The Coil-on-plug itself isn't going to make you more power, but it will let you run more boost without ignition misfires, granted all of your other ducks are in a row. I've run up to 28psi on the wasted spark setup using the Diamond coil pack and Magnecor wires.

Most "High Power" ignition systems are a bunch of snake oil.

[NICO]

i dont get any misfires at all!! when i do its time to change the plugs for new ones.

i was just think i should do this for my other motor build when i do run crazy boost, and to change with the times that subaru has change to the cop.

[Legacy777]

sorry i just seen your reply now.

ok take it slow, let me see if i have this right

bye looking at the pins on the ecu plugs i take the two wires i have pin numbers F47. 9, F47. 10, then i add two wires in empty spot F47.8, F47.7, run all four wires to the cop, then change the settings in the autronic to???

More or less, yes that is exactly what you do.

also how do i know what ecu pin takes what cyc #??

It really doesn't matter since you can the autronic which output is what. You just need to keep track of everything.

[Legacy777]

The Coil-on-plug itself isn't going to make you more power, but it will let you run more boost without ignition misfires, granted all of your other ducks are in a row. I've run up to 28psi on the wasted spark setup using the Diamond coil pack and Magnecor wires.

Most "High Power" ignition systems are a bunch of snake oil.

I've got the MSD Dis 2 ignition, and I've been pretty happy with it over the years. I believe it may have helped things, but it's been so long since I've installed it that it'd be tough for me to make a comparison especially since I've added/changed things.

[NICO]

ok i am make some progress now!!

what i did was take one of my extra legacy turbo wireing harness pulled two pins out so i can just slap them in to my wireing harness in my gc.

so i have all four wires now ready to go when i get my c.o.ps.

now what COP should i get?? i want to keep it factory so i have any problems with them i no where to get them. i all ready have a nice clean set of ej20g ones kicking around?

what ones should i get?? more or less.

[NICO]

all right guys i got all i need to make this work and it looks like its going to be nice and easy i hope!!

so i got a set of extra ecu pins from a wireing harness i got kicking around.

this is how its going on!!

step 1: add two extra pins on the ecu plug, which makes 4 in total for each signal on COP. get rid of ignitor, wire up everything like it came from the factory, like useing oem plugs. so i just add pins in extra slots to make it work nice and clean.

add pins


step 2: take coil pack out, there is 3 wires going to pack. take all 3 out of engien wireing harness. then i will have 3 spots for my new wires plus the 2 i add for 5 in total.

step 3: +12 wire is yellow wire on coil pack, so i plug my new wireing harness in this slot to power up COP. then the extra four wires i plug them in the slots to make the COP have signal on computer. set the Autronic to 4 and i should be good.

i make it sound easy becuse i have extra sets of wirring harness and extra everything i might add. i just got a wrx engien wiring harness to make this a real clean factory job!!

was a wrx wiring harness, now its a Subaru TecNico International wiring harness lol.


i just finished stripping the wrx wiring harness to take what i need this is what it going to look like, while still being plugged in the factory harness.

[Legacy777]

Cool!

That sounds like all you need to do.

Let us know when you get it fired up.

[NICO]

thanks Josh, i hope everything goes smooth but ill keep the post updated.

[NICO]

ok i tried out the set up and the car would not start!!


is there a order of coil like 1 2 3 4 that i must use becuse i dont know which one is what?

[def09]

Coils are all the same per cylinder. I think its firing order your after? 1 3 2 4

[NICO]

ok i got it to run but its wierd!!

here is the thing, i switched my autronic to 4 COP and the car runs on 2 cyc. when i leave it to 2 setting like the first post the car runs perfect with 4 extra wires in the system!!

then i siad ok let me try just useing the factory 2 wires oem style legacy turbo!! i put 1COP and 2COP wires together in the same spot as oem and 3COP 4COP wire together like it was factory and the car ran perfect.

how wierd is this??? 2 wires legacy turbo set up works perfect with COP and even adding four wires works the same!!

[PhyrraM]

That means that 2 or 4 cylenders are out of phase.

Cylinders 1 and 2 are on the same coil in 2 channel mode. Try switching them (1>2 and 2>1) and going back to 4 channel mode.

If that doesn't work switch them back and try switching cylinders 3 and 4. I'll be that one of those 2 sets is backwards.

[NICO]

OK SUBARU!!! i got them in and took it for a ride and WOW!!! smooth like butter and i need my ej20k heads becuse ej20g heads just cant rev that high to take advanteg of COP system.

it is amazing if pepole what to do this set up!!

i also found out from Ray ex autronic guy why i cant use 4 wires, so i did it like 2 channel legacy turbo and he says it ok like this.

""The plug-in ECU only has two ignition outputs. It is possible to get four, by making some changes the ECU and using other ignition hardware.

You need to remove the dwell board (small 50mm x 50mm board on top) and add chip in a socket that was hidden by the dwell board. Two wires will be needed to be added to the bottom of the ECU board so you get the other two ignition outputs on the main connector. Then use a four channel CDI and replace the coils with coils that do not have internal igniters.

Ray Hall""

i cant wait to tune it agian for some more boost!! its going to be crazy!!

thank you everyone for the help in this!!!

[93forestpearl]

I'm seriously considering COP's when I get those heads on. I won't have to run them in a wasted spark arrangement with my Link.


So you're using the black coils? I've been told I should get the grey units.

[Legacy777]

What's the main advantage of the COP setup? Better spark?

[93forestpearl]

I would say less work for the coils since you have one for each cylinder, instead of two coils firing twice as often.


I had been having trouble with misfires. I had to change my plugs at least every 2000 miles or so. I was on my second Diamond coil pack too with Magnecor wires.

When I get a car back on the road I think I'll go to COP.

[Legacy777]

I posted something in the engine forum about what appears to be a slight misfire around 3000 rpm. Plugs didn't seem to change the issue. Wires seemed to all be reasonably the same resistance. I haven't checked the coil pack, but it is relatively new. I suppose I need to check that, and will probably bypass the MSD to see if it changes.

My other suspicion is that it's just how it is....because at idle....I don't have any misses, and at higher rpms I don't have any misses.


There's only one little thing I noticed when playing around last saturday. Around the same RPM that I noticed the misses, I noticed more engine vibration. It was only within a certain RPM band. I didn't notice it at the lower RPM or higher RPM. That would indicate that there's a harmonic vibration occuring there. Just for kicks, I'm going to put the stock crank pulley back on and see if that changes anything.

[NICO]

I'm seriously considering COP's when I get those heads on. I won't have to run them in a wasted spark arrangement with my Link.


So you're using the black coils? I've been told I should get the grey units.

dont tell me that the gray ones are better!! they are not all the same!! i got mine free but they all use the same plug so i can change them down the road if i want later on if this is the case.

What's the main advantage of the COP setup? Better spark?

i noticed a diffrence right away wow it feels good!! about that 3000rpm miss you are so right!!!! i see it all the time in the j&s knock ! i add a bit of gas and i can get it to go away but its week in that section.

but the best part of this COP is that it revs and makes power more smooth and you can just tell that its running perfect.

with the J&s knock, there is a knob for sesative. i put it up all the way and i cant even get it to blink once with COP, but with the wires it would go off ever so slight at diffrent times so even that knows wires are week!!

its worth it, even my dad siad i was wasteing my time. i just kept telling my self then why did subaru get rid of those wires on the sti and wrx !! i know why now lol

[Legacy777]

So with the old wasted spark setup, you had that miss around 3000 rpm? But now that you've gone to coil on plug, you don't have it any more?

Since I'm still using the stock EJ22t heads, I'd have to mount coils on the frame rails or something like that, and run short leads to the plugs. So I may wait and see how the car runs with the Link and go from there.

[NICO]

So with the old wasted spark setup, you had that miss around 3000 rpm? But now that you've gone to coil on plug, you don't have it any more?

Since I'm still using the stock EJ22t heads, I'd have to mount coils on the frame rails or something like that, and run short leads to the plugs. So I may wait and see how the car runs with the Link and go from there.

yup right around 3000 4000 i had that miss, every time i would stab the pedal on off on off it would light up. its wierd becuse i all ways keep everything new and it would do it all the time. i would change the plugs and it would go away for like 2 days then do it agian.


also becuse i have to new set up i use bkr7 copper plugs i gap them to 25, could i run a little bit of a high gap now you think?

[Legacy777]

Did the miss happen just revving the engine when the car is sitting, or did you notice it while driving?

What exactly is the J&S monitoring or displaying? I thought it's supposed to detect knock....or does it notify you on misfires as well?

Do you mean you have to run the BKR7E-11 because of the newer heads, or is there another reason?

What kind of boost are you running? What do your plugs look like, do they look fouled or like they're running how they should be? You could probably gap them a little more.