COPs for Dummies... a writeup
 

COPS for dummies:

The following write-up is an attempt to consolidate my experience with my conversion to COPs. It’s a fairly comprehensive accumulation of everything I did to make mine work. In the end, it really didn’t take anything to make it “work”, just fab the harness and plug it in. But it took me awhile to get everything in order and start the job. Hopefully this helps some other guys on the fence. There is going to be a certain amount of insulting your intelligence in this thread, but it’s things I screwed up, so hopefully something in here saves each of you who are going to do this a little time and effort. Here goes.

My setup is a 1.6 running Megasquirt standalone, so be sure when you make your harness, you are following the correct diagram in the first link below.

Here are some links:
The original DIY COP by Braineack in "useful saved posts:
THREAD#1: https://www.miataturbo.net/forum/showthread.php?t=12704
The continuing monster COP thread in the DIY forum:
THREAD#2: https://www.miataturbo.net/forum/showthread.php?t=4756
My original I Love COPs thread:
THREAD#3: https://www.miataturbo.net/forum/showthread.php?t=18565

I also highly recommend you do a title search for COP and COPS and read all the most recent threads about the subject to be sure there isn’t something new that we’ve discovered.

I purchased 4x 2000 Corolla 1ZZFE COPs from a described 10k mile car. They were in perfect condition and came with the fuel injectors from the Corolla that’ I’ll try to unload on eBay. I paid $60.

I purchased 5 connectors from the source in THREAD#1. I wish I’d bought nine. During some experimentation, I hurt one of them bad and couldn’t use it. Then I didn’t really like my first wiring harness and wished I’d had 4 more to make another one and do it perfect. I recommend you buy 9 connectors. One is to screw up, and then you have enough to make 2 full harnesses.

I got my connector pins from Brain, but he’s out. You’ll need to buy yours from the source in THREAD#1. You’ll need 16pins, but I recommend you just buy 100 and you’ll have enough for 2 harnesses, plus screwups, plus you can hook a bro up who might need some local to you.

The wire I bought at RadioShack. It’s an 18 guage 3-pack. I noticed that the individual copper strands of each RED/BLACK/GREEN wire are different. The BLACK wire is just 5 or 6 heavy strands, while the red one is about 30 hair-thin strands… the GREEN one is in the middle. I used the BLACK for GROUND and TRIGGER. The RED for 12vlt, and the GREEN for TACH.

I bought a spare ignitor from a forum member. In the end, the ignitor was way more pain than it’s worth. Soldering the wires to the leads in the ignitor is a chore I wouldn’t wish on anybody. My experienced recommendation is to just solder some wire-ends onto each wire and and connect them directly to the harness, leave the damn ignitor out of the loop.

My Megasquirt standalone required a resistor to facilitate the tach signal. The best place to put it is in the DIAGNOSTICS BOX. I cover this thoroughly in THREAD#2.

To make sure you’re fab’ing the harness the proper length, I made a template on some cardboard and placed the COPS on it in the exact separation they’ll be installed. Each wire I cut and soldered I just made it the appropriate length by measuring the distance with the COPs sitting right in front of me. The distances don’t have to be down to the exact millimeter, but within ½” or so. Don’t forget to space out your splices on each wire. The last thing you want is a 1” diameter cluster of splices all in the same spot on the harness… just spread them out ½” or so, and don’t forget that the shrink-wrap will give the splice a little extra girth as well.

STEP#1: Lay out the wire and start cutting/stripping/soldering. I put all my connector pins on as I went… and made sure I when I put them on, they were already as lined up as I could make them, so I didn’t have to twist the short 1” piece of wire coming off the main harness 180* to fit into the connector right-side-up.
DON’T FORGET TO SLIDE YOUR SHRINK WRAP ON BEFORE SOLDERING!
If you’ve never soldered wire before, just practice a little. The key to soldering is that solder isn’t paint. You don’t solder over the top of the wires… you get the wire hot enough that the solder soaks into the wire and bonds each strand together. There’s a series of pictures that shows this perfectly.

STEP#2: You can actually do this well before step 1. Once you’ve got the harness fab’d up, you need to Dremel a little bit off of each pin so it’ll seat properly. Reference the pic. I wish I’d done this while they were all still all on the factory strip so I could make them all perfectly uniform. However, I waited until the harness was done and did them just holding each one in my hand while I Dremeled. Not to big a pain, but it would have been easier/faster/better to do them on the strip.

STEP#3: Pushing the pins into the connectors. They’ll only go in ONE WAY. And they’ll click in place. If you push them in as far as they’ll go and don’t hear a click, then you probably didn’t Dremel enough off. They also don’t seat very tightly once they’re in… the pins will wiggle around in the connector a bit. Also, once you put a pin in the connector, IT’S IN THERE!. And you’ll destroy the connector if you pull on it hard enough to pull it out. That’s why you buy a few extra.

STEP#4: Don’t forget the extra Ground wire. You'll want to place your harness roughly in place on top of the valve cover to see where exactly you want to splice it in. I think mine is about 6" past the #4 connector... enough room to route the harness through the brake vaccum hardline and the fuel lines. Just make the ground splice itself a foot long and trim it to perfection later.

STEP#5: Gutting the ignitor. I made 5 small holes in the back of my ignitor instead of 1 big one… made sense for the wires to come out of it as straight as possible. The middle hole was slightly bigger as it included 2 wires. But again, I recommend you skip the ignitor and just put wire-ends on.
The metal ignitor cover is on there pretty good. I didn’t drill mine as recommended, but rather put a small flat-blade screwdriver in the bolt-hole and pried one side up… then used the screwdriver along the edge. The inside of the ignitor box is covered with this jelly-like cummy sticky stuff. It sucks… and it sucks some more. There are also some metal pins that may be stuck to the cover. Just pull them off gently, you don’t need the flimsy bendy little pieces of metal stuck to the main ends. Once the little bendy pieces are pulled off, gently pry the ends up and straighten them so they’re sticking straight out… makes for easier soldering.
Then do your best soldering on the ends. It’s tough in there with the shrink wrap. You get the soldering iron close enough to it that it shrinks just a little and you may have the nip the shrunk end of the wrap to get it to slide over your connection.
It’s also recommended to Epoxy your wires inside the ignitor… I just wrapped the gutted ignitor in electrical tape seated it back down in the stock location.

STEP#6: Now that the harness is finished, test it.
Pull the spark plug wires.
Unplug the coil pack.
Unplug the ignitor.
Drop in your COPs.
Connect the harness to the COPs.
Ground the harness.
Plug in the gutted ignitor, or just slip on your wire ends.
Install resistor in Diagnostics box if necessary.
Turn Key.
If it fires, move on…if not, troubleshoot.

STEP#7:
I wrapped my entire harness in electrical tape… over to you how you want to finish it. I may get some plastic corrugated wire wrap to make things neat, but not this week.

STEP#8:
Making the COPs seat perfectly. COPs come in lotsa shapes. The Toyota ones are real easy to modify with a Dremel to any shape you want. I modified them a lot… basically just by removing the small bracket on them that holds them in place on the Corolla. You want them to seat perfectly flat in the valve cover channel. But you’ll probably find they’re about 1mm-2mm’s too wide. A little flattening of opposite sides will allow them to fully seat onto the valve cover. The rubber seal will allow a little compression, but make sure the walls aren’t pinching the COP and holding it up. Be sure to flatten out the rubber seal in the same area as you’re removing plastic… that’ll ensure the seal doesn’t bow.

STEP#9:
Once the COPs will seat flat, you’ve gotta find a way to keep them in place. You can engineer whatever method you want. Some guys weld or JBweld individual nuts onto the valve cover, or drill completely through it and use a threaded post. That’s too much work for me. I don’t know how it can get any simpler than what I did.
The key to the way I did it is that the 3 bolts in the middle still need to keep pressure on the center of the valve cover to make sure it seats tight to the head. You want the locking plate hold the COPs in place, but not be under any pressure of actually holding the valve cover to the head. The pressure of holding the valve cover to the head now rests on the brass spacers. If you grab the COP, you can still wiggle it a little with some force, but it’s pushed the perfect pressure down against the rubber seal.
The spacers are made from a piece of 5/16” round brass stock, but there are options depending on what they have at your hardware store… I bought all my stuff at Taylors’ DIY Center.
The hold-down piece is just a piece of 1" mild steel stock. It's not real thick, but stiff enough not to bend too much when pushing down on the COPs. I wanted a brass piece, but they' weren't long enough. You could just as easily use aluminum.
The holes on the valve cover are 6x1.0x80mm metric. I found an 80mm bolt length was just a little too long, so I cut a few threads off. The holes in the head that the bolts insert into are finite in depth, so you actually do have to monitor the length of the bolt, or it’ll be all the way in, and not be touching the plate yet. It’s just a little trial and error. Measure the depth, cut the spacers, install… cut spacers down a little, install… cut spacers a little more… bolt bottoms out… Dremel another 2 threads off bolt… install… cut spacer one last time…. Ahhhhh pefect.

STEP#10: Remove the coil-pack.
This step is not necessary. You could simply remove the plugwires.
The coil-pack is held in by 3 bolts. 2 are on the front sides, 12mm, very easy. The one in the back, 12mm, is a bitch. A box-end or open end is your only option. I had to drain my radiator and pull the heater core hoses to get enough room to make it happen. I also just left the plug wires on it in case I ever need to re-install, one less thing to look up. Tuck the stock wires for the coil-pack down below the CAS.

STEP#11: Install everything permanently.

You’re done. My beautiful black crinkle valve cover is another story.

There are a lot of pics… you should be able to match them up with the steps.

More...

And more...

Some more...

Wait, theres more...

And I'm spent...

Wowsers, nice rightup! Your valvecover looks great.

ill be following this, thanks

Sam nice write up. Truly a SpamNavy quality post. A couple of notes for posterity:

1. To remove the pins, pull the white locking clip out of the conneciton side of the connector. Then reach in with a narrow flat blade screwdriver and gently lift the black plastic springy tab up from the pin (it snaps into place behind where you dremel). The pins should pull out easily if you get it right.

2. Soldered connections in a car are not as reliable as crimp connections. Solder connections create a stiff joint immediately adjacent to a flexible wire that can vibrate and break over time due to fatigue

I recommend using high quality, high temp crimp connectors sized for the application. I think 18 AWG sized ones are red. The good Nylon ones are translucent red and much more durable than the vinyl solid brick red colored ones. Better yet, you can get heat shrinkable self-sealing versions of these for a little more dough. Worth the price for reliability. Google "heat shrink butt crimp" to find them.

The "crimped vs soldered" debate has been going on for quite some time...

Part of the argument is the "stiff joint next to flexible wire". Well let me think here...in a crimped wire, don't you have the crimped section aka "stiff joint" followed by flexible wire?

By the way, I have never seen a soldered joint fail but have seen countless of crimped wires corroded right through.

Call me old school, but I will stick with soldered connections and proper routing of the wiring harness.

Tony

yeah i know the debate goes on. i've had RC car solder joints fail before. not quite life threatening but still. the deal with the butt connectors is that there's a little strain relieving since the crimp is further inside the tube and the transition is gentler. plus the shrink tubing version offers some semi-flexibility between the crimp and wire.

The other point is in a solder joint you have solder wick back up the wire and the wire becomes stiff. In the crimp connector the wire has some give to it to survive any flex. But this is an issue that will never be resolved.

Thanks for the kudos. I'll be more than happy to ad any more hints/advice/technique in the main body of the writeup, but you'd better let me hear them before my 24hr edit timelimit is over.

SpamNavy, very nice pics. Very helpful to the uninitiated.

One thing. You said "My experienced recommendation is to just solder some wire-ends onto each wire and and connect them directly to the harness, leave the damn ignitor out of the loop."

Why? if you're gonna do that, why not a whole new connector from radio shack? Is the soldering inside the ignitor that fussy?

If you have things you want to add/change just post them in an extra post and say where you want them. I'll fix it for you if it's over the 24hr limit or w/e it is.

Soldering inside the ignitor was a nightmare. I've got a great small/accurate tip for my soldering iron and it took me about an hour to solder up 5 connections. Using the gutted ignitor as just a method for making use of what's there... but it doesn't buy you anything except retaining a factory look... and actually is one more junction that the signals have to pass through.

Here's what I'm talking about. Just connect the 6/5 wires on the end of the COP harness directly to the leads of the ECU harness... forget the ignitor.
https://www.miataturbo.net/forum/att...1&d=1206632240

Okay, but if you're going to do that, why not just cut out that connector entirely, and splice the wires? Each wire could be individually shrink wrapped, and then taped or shrink wrap over the bundle. As long as you're soldering on the car, rather than at a bench, why keep it stock at all? Is there something else that goes through that connection that you need to keep?

Because then you've made the COPs a permanent installation.
Right now, it'd take me about 10 minutes to convert back to standard ignition. If you cut the factory harness to the ignitor, then you'd have to cut/splice/solder all 9 wires back together again to return to stock... makes no sense.

Nice writeup :) I just made the mounting plate a few days ago for mine...

http://i6.photobucket.com/albums/y24...1/DSC00221.jpg


And now im waiting on the toyota dealership for the connectors.

Hi guys, do you think that the cops from a '06 Toyota SIENNA (part number 90080-19025 ) will work in a miata? (+emu)

They looks like the cops you are using from the 4l, but they are from a V6...
Should i buy them (really cheap) and try? :m-freak:

Here it is: http://www.yowjung.com/product/DirectCoil-l.pdf
Page 5.

Any reason why they should not work?

Theoretically, you should be able to wire up any coil out there.
As long as you have the ability to manipulate the dwell, trigger, etc... you should be able to get any coil to fire.

But the coil has to fit in the valley of the valve cover, it has to fit through the hole, and it has to reach the spark plug. The 1ZZFE Toyota Coil itself is perfect in it's dimensions... it fits perfectly. And somehow the stock Miata ECU is close enough to the Toyota ECU in it's signals that it fires perfectly.

And you can get a set on eBay for cheap.

Thanks for the great writeup. I am looking for some clarification though. I have a 1997 that I am switching over to COPs. What is the connector on the CPU side of the harness. I know what connectors I need for my ignitors, I just don't know what the plug is on the other end. Am I correct in thinking that it is part of the ignitor that is already on my stock setup? If so is there a place where I can just buy the connector? I would like to be able to switch back to my plug wires at a moments notice.

Allow me to jump in here quickly before Sam wields his fabled Staff of De-Noobification.

I (and I presume, we) have utterly no idea what the hell you're talking about with this CPU-side business. If you're referring to the two three-pin plugs on your engine wiring harness that used to plug into your stock coils, then that's where the connectors are- on the stock coils. I'm not aware that anyone has a good mating connector for them- either splice into the factory harness using vampire taps or hack apart some old coils and liberate them of their connector.

In your '97, the factory coils (two of them) each had an igniter built in. So each of the two three-pin coil connectors has a ground wire (black), a +12 wire (blue) and a trigger wire which is +5 active-high from the ECU (brown and brown / yellow.)

http://img33.picoodle.com/img/img33/...Nm_8bd031c.gif

Thanks for the help. That answered my question. I am definitely a noob and sorry for the confusing description. I just had a hard time figuring out how to describe it.

I haven't torn apart my ignition yet so I am not sure about this next question.

If there is a ground, a +12 and a trigger going to the 2 stock coils, where am I supposed to wire the tack to? Is there another connection further up the pipeline or is this not even applicable on this model?

Ahem... I see my services are needed.

Hey NOOB, allow myself to introduce myself. I am Sam (although there are many Sams and many threads, this thread is mine) and since you chose to make every NOOB mistake I can think of and defile a thread I started, here you go.

SEARCH NOOB-FUCKER!
A title search for the word COPS reveals 37 threads. The 17th of 37 threads reveals:
COPs for dummies... for the 1.8
https://www.miataturbo.net/forum/showthread.php?t=20008

And stick something in your profile before I get mad and change my avatar to a picture of your mom bent over my hood. And then go to the NOOB forum and make an intro thread to redeem yourself. And welcome. And we need pics or you won't like my new avatar.

Thank you Sensei for your great wisdom.

Oh and by the way you've got a dead link there pal. :)

Wow Sam. That is terrific.

OMG OMG OMG OMG OMG OMG OMG OMG OMG OMG!!!!!!!!!!!!!!!!!!!!!!!!

Corky told me I did something good to my Miata.
That's like Jenna Jamieson saying that you were good in bed.

I just wanted to say thanks for the info! I don't post up on here much, but this is just the info I have been looking for. I should be all setup and running soon.

I am doing something just a bit different though. I'm using a plug and socket from an old Honda wiring harness on the harness side of the OE miata coil plug (I have a 95 1.8l). I have two connectors for it, I'm soldering one to the original coils, and the other to the COP wiring. That way I'll have a easily reversible 1.8l setup. I'll post up picks after solder everything so you can see what I'm talking about.

Plus I need to use all these extra wiring harness connectors that I have left over from my Honda builds!

Anyways, thanks!

where can i find wiring diagram for the COP conversion that makes sense for my 93 1.6. Im trying to make my AMX07 Miata run as good as it looks.

You're shitting me, right? Hahaha, that's a good one. I mean, it's not like that info isn't linked in the FIRST FUCKING POST IN THIS THREAD! :noob:

Looks like my hold down plate :). My True Value hardware had silverish tubing in their misc metal tube/etc... section. For those that don't want the Brass or have the bother of painting it.

Great work on the writeup.

Search button, use it!
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

hmmm. if this writeup is for dummies to understand, what does that make you?

Thanks! Great write-up...

is it going in the wiki or stickies somewhere

Sam, thanks for the great write-up.

After reading some 21 pages of the Lazzer's thread, I came across yours.
And, really, only this step was baffling me, but, now, I think I understand.

The signal sent from harness gets processed by the ignitor, gets sent to the coil pack, which generates stronger current, which is then sent to the spark plugs.

By plugging the COP harness, I will no longer need the coil pack (that's pretty obvious), and, seems I no longer need the ignitor, although leaving it in place won't do any harm, right?

So, as long as I piggyback a connector onto the ignitor plug (just so the COP harness can be removed to revert to stock), all I should do is unbolt the coil pack. :D

Right?

Thanks!

(i hope i don't get flamed for this)

I asked railz to make me a COPs harness. I soldered on the connectors myself and tested the harness with a multimeter for continuity (only positive, not negatie.. IOW i didn't make sure no other pins had continuity when they shouldn't..)

I tried to fire it up and eventually iit ran on 2 or 3 cylinders.. I originally set dwell to 2.5ms for crank and run, but had to go to 5 to get it to fire up.

I trimmed down the COPs' plastic bases so that they would sit further down a into the well and tried again, but this time it wouldn't start at all, though it sputtered a few times.

So quick question #1 -- i see on the other threads that the harness is supposed to have a ground lead to the block.. the harness i got from railz doesn't have that.. should i take it apart and add one? Is it required?

#2 -- is there any way to test all my coils to eliminate them as a problem?

---------- EDIT -----------
Problem solved... the harness was set up where cylinder 1 'branched' off instead of being the trunk and cylinder 2 was the 'trunk', so i accidentally had them switched when i installed it.

Now running on all 4 cylinders!

FWIW here's how i did my hold-down bracket:
1) buy some 1"x1" right-angle aluminum (i bought this for strength, much less flex than flat stock)

2) buy two approx 2" long M5x0.8 bolts / machine screws. (My valve cover was already messed up, there were sheet metal screws holding down the wire guides, no bolt i found was an exact thread match)

3) drill two holes in the flat stock matching the points on the valve cover

4) cut up some left-over silicone hose into little .5" x .75" rectangles and glue them to the top of the cops to provide some cushioning / take up the slack

5) mount the flat stock and enjoy



Thanks,
Tomaj