Swapping EJ25D phase I/II coil packs DIY/HOW-TO

[Garrison]

So I bought a new coil thinking it was for my car, it was not. So now I have a later model, EJ25d coil.
I ordered new NGK plug wires because the seller told me they would fit my car. They do not, so now I have new wires.

As I'm combating the heinous and ever-present misfire cyl. #1, I have resigned myself. I'm just going to swap the packs, if it can be done. I took the old one off when I got off work today, but the two packs are very different. Crossed wires, too bulky, etc.


So I'm asking for help! What needs to be done here? As you can tell by looking at the pictures the problems aren't super complex, but I would like a little heads-up if possible. I looked up the MSD coil and neon coil, but as far as I can tell no-one has done this particular swap yet (which is kind of weird because the new-er style coil-pack is supposed to be far superior from the old). I know for sure I need longer bolts, but I'm not sure about the wiring.... Are the terminals the same, straight across 1-2-3?

Pics:

Old pack
https://sl-i.net/FORUM/images/imported/2012/03/IMAG0408-1.jpg

Old pack wiring
https://sl-i.net/FORUM/images/imported/2012/03/IMAG0411-1.jpg


New pack
https://sl-i.net/FORUM/images/imported/2012/03/IMAG0409-1.jpg

[mike-tracy]

So what works for wiring up a neon coilpack doesn't work for swapping phase I-II coils

Benfolio's home-made harness (his colors are different from yours since he's doing a non-oem coilpack):
https://sl-i.net/FORUM/images/imported/2008/04/coil3-1.jpg

If I remember right a neon will have the right longer bolts, or otherwise you can grab them off a phase II subaru engine.

[d1giPhux]

^ You have any more info on that harness he made?

I swapped my coil pack out with an MSD, however I cut the harness coming from my car. What a shitty mistake that was. I might go back to testing the MSD coil, but I need to create an adapter harness that will work using the stock wiring coming from the Legacy GT.

[Garrison]

My understanding of it is to make a new harness with a spare one of these, mated to your harness for your coil-pack.
Why is it a shitty idea to cut the stock harness?

Basically, a spare one of these
https://sl-i.net/FORUM/images/imported/2012/03/Untitled1png-1.jpg

Plus this
https://sl-i.net/FORUM/images/imported/2012/03/Untitled2png-1.jpg

[d1giPhux]

I cut my harness and it was a nightmare. Started getting random CEL lights for no reason. It would throw 'misfire' CEL codes on all cylinders, or random cylinders, etc. Re-wired the stock harness.. and still haven't sorted the problem out. I'm still trying to figure the issue out, but my car is off the road for now due to brake line work. Once i get it back on the road in a couple days I'll hopefully be able to figure it out. At first I thought it was the neon MSD coil, but now its looking like the problem stemmed from cutting the wiring harness that comes from the car.

[Garrison]

Update:

The trick to wiring the new pack in properly is simply to match the colors.

Blue goes to Blue
Red goes to Red
Yellow goes to Yellow

https://sl-i.net/FORUM/images/imported/2012/03/IMAG0412-1.jpg
https://sl-i.net/FORUM/images/imported/2012/03/IMAG0413-1.jpg

[phi11]

Blue to blue
Red to red
Yellow to yellow

I did this on my coworkers car last week.

[chuckthefuk]

solder + shrink wrap!

[Garrison]

Blue to blue
Red to red
Yellow to yellow

I did this on my coworkers car last week.

QFMFT ^^^^^

Thank you! Someone get this man a cookie. :grin:


solder + shrink wrap!
Not available at the moment, but these terminals are solid; I tried to pull them out and they refused to budge. I'm comfortable with how it's setup right now. When I make a custom mounting plate, I'll redo it. Thank you for the advice though :smt023

Proper wiring:
https://sl-i.net/FORUM/images/imported/2012/03/IMAG0415-1.jpg

[mike-tracy]

So it works? Any change in how the engine feels?

[Garrison]

Mike,

Yeah it did work, as Phil said just match the colors.
I love the changes, butter-smooth idle, a little more power all over, more responsiveness at the pedal; honestly my favorite change is the massive reduction in chugging at low rpm. Dunno if it's the wires or the coil, but it's a good change!

[Garrison]

Update:

I ended up not making a mounting plate for my coil, big mistake. The vibrations from the engine have killed the coil pack and I'm now getting the misfire codes again. I'm going to grab either a neon coil, or MSD coil and try again. This time I'm breaking out the machine shop to do it properly by making a solid mount for it. I think I actually remember a thread about how-to, somewhere on here...

P.S. What is this?:

http://www.ebay.com/itm/AEM-High-Output ... 76&vxp=mtr (http://www.ebay.com/itm/AEM-High-Output-Inductive-Dumb-Ignition-Coil-30-2852-2-PACK-/330757040502?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ASubaru|Year%3A1999&hash=item4d02a7e976&vxp=mtr)

[r3v_v3ng3]

FWIW next time just depin your old connector and repin it to the connector that fit the coil. Cleaner install and wouldn't have problem touching wires or such.

[r3v_v3ng3]

That aem thing looks like its for individual coils on a cylinder. Seems like its for their standalone ecu that can control spark on each cylinder