on the side of the coil with the numbers and letters mine are different. top left is : 04609 bottom left is : 088ah bottom right is : 0525. im not sure if its a different coil as i bought it already built, but all 4 are matching. maybe the ones you have are from a different car.

Upon closer visual inspection, I found this. Now, I'm wondering when/how this happened? It clearly got hot...



I tested all the coils I have. They all measure 0.6 - 0.8 ohms (testing between the 2 connector terminals). Even the bad coil measured ~0.6, so I'm going to make the assumption that testing the coil's resistance isn't a very good way to tell a good coil from a bad one.

Quoting Vader:

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How long have you been running that particular cop setup?

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This system has about 2,000+ miles on it. I also used it on 1813 for a while, so some more can be added there.

I don't believe testing a coil with an ohm meter will give you the results that you are looking for. The coil winding's are far to small and spaced to closely together for your ohm meter to push a voltage through. If you had access to an megger to actually push a variable voltage through the coil, you could possibly get a result.

I would say at this point figure out where the coil harness is grounded and check/clean the ground. Replace the pigtail pictured and associated coil. If your still in the dog house after that i would be looking in to building a new cop harness. Are all the connections on your harness soldered or did you use asshole connectors?

I've had a cop set up on #224 for about 4k with out any problems and we're both using the same style coils.

The COP systems do change the way the spark current flows to ground, compared to the stock dual output coils. So a good ground to the head is more important than our OEM configuration. But that probably isn't what you are seeing here.

It looks more like long dwell(or excess energy in) is leading to severe overheating. A short in the wiring would do it too. I'd tell you about all the coils that I melted in a similar fashion while testing ignitions, but then you'd want proof.:) Maybe the problem is being made worse by underhood heat. Is your alternator output good?

Just out of curiousity, are you using the COP on an otherwise stock ignition? If so, it is generally a performance downgrade from the OE coils, comparing new to new.

Just FYI I'm running a magnus SMIM, factory coil, factory wires and all it took was the ~40 dollar JMF coil bracket, fits great.

Quoting GSTwithPSI:

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I am running the COP system on a stock ignition system (no CDI box). The main reason for this is because of my Magnus SMIM. There's not a great place to mount the coil pack where it still looks clean...at least not as clean as the COP system. In addition, the area I want to custom mount the stock coil requires extra long spark leads, which need to be purchased individually. A typical wire set wont work for a remotely mounted coil pack. In short, the COP was just an easier option for me at the time. At this point, it is proving to be more of a pain though, and I'm looking into other options for an ignition setup.

So, if keeping the COP is my goal, what would you suggest, Bradrs?

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The problem with COP is that the dwell from the ECU doesn't work optimally with the dwell for the coils. A CDI like the ARC-2 is a quick solution. A really nice guy even went out of the way to make them plug n play.

But to be honest, I'd want to track down why you are burning up coils before changing the coils out. It could be something else causing the issue. And if so, changing the ignition may not solve the problem, you might just wind up with a burnt out CDI box too.

Have you double checked your wiring to make sure the coils are in series as they should be. I have occasionally seen people wire them in parallel. I'm surprised your PTU wasn't fried also. Does the PTU still seem to work? It that makes me wonder if there wasn't a short that was the cause of the coil being cooked, because a PTU can only supply so much current on these cars.

That install looks like it is wired correctly, but (and I don't mean offense to the guy who wrote it) that looks super ugly to have that many solder joints all over this one little subharness. I understand he did it because he was working with a bunch of precut pigtails, so he did what he had to connect them.

One thing to keep in mind with your ground points on your head. I can't tell if your valve cover is painted or anodized. But anodized aluminum doesn't make for a very good ground path either. On the stock coils, the spark current basically recirculates across the head and doesn't go to the system ground. But with the COP, you are completely changing the spark ground path, so that it has to go through the system ground.

On electrical circuits, current flows in loops. It will flow from 12V to ground through a load, but there is also a matching current going from ground to 12V through your voltage supply(or battery). This is a basic electrical theory. So when you picture the spark current, you need to draw the loop. I really should make drawings for these sometime to post them.

The dual ouput coils are very simple. Each end of the secondary is tied to one of the plug outputs. The voltage is generated in the coil secondary. This causes current to go out one plug wire, to the plug. It jumps the gap, goes to the head. Then it goes to the other plug, back through the gap, up the plug wire, and into the coil. That is your loop. And it doesn't really use vehicle grounds for anything on the coil secondary.

Now if you have a single output coil, it is wired differently internally. One end of the secondary goes to the plug, and the other end goes either to a ground post, or it is tied back to the 12V line.

Lets look at the case where it is tied to the ground first. When the coil fires, the current goes down the plug wire, to the plug, jumps the gap, goes to the head. From there, it has to get to that ground post. On the coils you showed a link to, it is a pretty straightforward ground path. But if it is tied into the vehicle ground elsewhere, the spark current has to get to that location through the vehicle grounds.

If the coil secondary is designed so that it is tied to 12V, then the path is even longer. It goes through the coil, plug wire, gap, to the head. Then it goes to your system ground, through your charging system/battery to the 12V/feed wire that feeds the coils.

If you have paint, anodizing, or any other coating that blocks these current paths, you can run into issues.

The real problem with using other coils, is getting the dwell right. That is why the CDI simplifies that. But if you are just trying to use the coil, then you want to pick one that is similar enough to the DSM so that it charges well enough, in the same time as the DSM. BUT, you don't want to charge much more than that, because the stock DSM ignitor limits you to about 6-7A. You can use workarounds on this, but most are complicated, or not cheap. And I don't think that anyone right now is adjusting dwell times with a factory based DSM ECM.

That was an Evo in that 25 page link right? I didn't read it all. But if it is an Evo, then it will wire differently from a DSM, since their PTU is basically built in to the coils. And I know some Evo guys have figured out how to adjust their dwell in their ECU. Aside from that, I don't know enough on the coils to say if it is a great idea or not. But most of these swaps have their issues.

You need hayabusa pencil coils. Quit being cheap. Or these high output coils (smart/ dumb) >> click

Forget about the aem pencil coils in the link, those are only good to about 15 psi.

Quoting G:

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You need hayabusa pencil coils. Quit being cheap. Or these high output coils (smart/ dumb) >> click

Forget about the aem pencil coils in the link, those are only good to about 15 psi.

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Hayabusa pencil coils, eh? Could you draw up a wiring diagram and show me how to wire them in?

I've noticed you throwing around the term newb an awful lot lately. What's ironic, is in just the few years I've been here, I've never once read one of your posts and said to myself, "Damn, this guy knows his shit". Quite the contrary, actually. I read most of the stuff you post and just lol at the amount of incorrect or misinformation.

Maybe you should stick to crying about rust, peddling overpriced parts and posting when parts are NLA

Quoting bradrs:

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The last time I looked at the EyeAbuser pencil coils, they were a horrible match for the stock PTU.

The other coil is a strong coil, but it also wants a lot of current, and I'd be concerned about dwell time being too long for these, over time. I suspect they'd run great for a while if you have your wiring done right though.

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When you say wired right, would that differ from the diagram I drew above? I basically just adapted the Denso coil in place of how an intrepid coil would be wired into the system. Thanks for the help.

No wiring diagram? No part numbers? That's what I thought...

You haven't posted a one error? What about the time you said the stock heat shield on our cars was made of aluminum? How about the time you said the FP mani doesn't ever cause heat issues? Or how about the time you claimed logs could be produced that show IAT temps lower than ambient by using aluminum IC piping? Or how about your theory on making more power with a 154* T-stat? Wait, wait, wait...lets not forget how you price items separately when you're only willing to sell them in pairs...then calling other members stupid for not being able to do math. Those are the one's I remember off the top of my head. Seems to me like the majority of your posts are errors. If all I did was spray paint the under dash and change the oil on my car, maybe I'd only have one error too

You've been around here since 04' and act like you haven't learned a thing from the knowledgeable group here. Maybe you are better suited for an extended membership over on T00ners?

I'm fine with posting up my mistakes here. I've got pages of shit I've fucked up. Hell, I pulled a motor out of 1813 because I forgot to tighten up one of the adjustable cam gears and misdiagnosed it. Currently, the front wheels on 1837 don't fit because of a big brake upgrade. Ooops

Here's the difference between you and I. I can talk about what I've done, and show others how to avoid the mistakes I've made by posting it up here. I've got thread after thread of failures and successes. What do you have?

Yet again...NOT. SHIT.

You talk like you're all knowing, but I haven't seen anything out of you to back it up? Like I said, stick crying about rust, peddling overpriced parts and posting when parts are NLA and you'll be right at home here. Start giving technical advice, and judging from your past you're just going to make yourself look silly per the usual. GTFO, G.

Quoting G:

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Per the usual, I hear a lot of talk and don't see shit else coming out of you. Called it.

You forgot more than I'll ever know? That's hilarious, seeing as you thought you botched up a timing belt job...the epitome of newb mistakes in regard to the 4G63.

And who posted to bail you out? Yours truly. ---> click

What a joke. Don't worry, G. I'm here for you