M44 Coil/COP wiring questions

[DataTraveler]

I really wanna change over to COP mainly for the troubleshooting aspects and lower maintenance cost, as you don't need plug wires anymore, and I'm cheap.

I also HATE hacking OE wiring harnesses. Can lead to troubleshooting nightmares down the road, turns off buyers if you ever want to sell, etc.

Anyone know of a way to get just the plug end of the coil?
Anyone have any pics of what that plug looks like, inside and out? (It's cold here and I'm allergic to snow lol) I don't even know at this point if I could salvage a usable plug from a bad coil.

I'd like to be able to make my own wiring harness from the OE harness to the new coils and NOT modify the OE wiring in any way. If I do ever sell it I'd like to have the option of putting the OE parts back in.

[osu_ti]

I did this a couple of months ago. I used an E46 coil wiring harness and cut up a stock coil pack and used the plug on the end of it. I soldered the E46 wiring harness to the correct pins on my newly made plug and it works great. I took pictures of the finished product, but I've yet to post them. I'll try to post them up tonight.

Butchering a stock coil to make a plug out of it took quite a bit of work. I spend a good deal of time first with a hacksaw then a dremel to reveal the leads I could solder onto. All of the electricals in the coil pack are set in some sort of epoxy.

I'll also warn you that the wiring diagram that I found for the spark signal to each cylinder was incorrect. I had to use trial and error to find which wire was for which cylinder.

[DataTraveler]

Your post in another thread was what gave me this idea heh...

Any chance you kept track of the correct pin out etc?

And where is the incorrect wiring diagram from? Bentley?

[osu_ti]

Here's how mine turned out:



I didn't take any pics of hacking up the coil to make the connector at the bottom of the screen, but all it involved was exposing the solid copper leads on the inside with a hacksaw and a dremel.

The wire color to cylinder correlation (for my car) was

white - cyl #1
blue - cyl #2
red - cyl #3
yellow - cyl #4


My findings were contrary to the information found here:
http://forums.bimmerforums.com/forum....php?t=1103482

Perhaps different cars had different wire colors??


As far as a performance improvement goes, it seems to idle better (but I also put new plugs in at the same time - old one's didn't look bad, though). It also cleans up the engine bay a little and is cheaper than replacing the coil and spark plug wires.

I bought 6 coils and the E46 wiring harness off ebay for ~$130. A buddy of mine used to be in the e30 M42 COP plate making business had a couple left, so I got one from him.

Let me know if you have more questions.

[DataTraveler]

Awesome thanks!

I'll have to compare that diagram to the one in my service book when I get home. Maybe buy the wiring diagrams off J!m too