92Yata

Toyota Cops Turbo Miata Crank No Start.
I had recently upgraded to toyota cops without any issues on my 1.8 swapped turbo 92 miata..
I bought a prefabbed wiring harness that plugged right in where the igniter would. Plug and play.
It came with a set of OEM Toyota Cops and aluminum bracket with standoffs for mounting.
It also came with a resistor to install in the diag box to get the tach working in my 1.6 car.
I only needed to change spark dwell settings in TS to 3.5 Cranking and 2.5 running and overdwell to 6. I ended up using 4.0 for cranking and 2.6 for running.

I have run these for a couple of months.

I went out one morning to a crank no start scenerio.
Plugs seemed dry and suspected the CAS had failed.
Sometimes it would start then just die seconds later.
I swapped in a known good CAS and started the car and set timing.
Minutes later I was back to the same scenerio with a crank no start.
Plugs also seemed dry.
Swapped in another CAS I had with no luck. WTF.
So I looked at a different plug and noticed it was a bit wet.
I decided to pull the cops and reinstall the original coil pack and it fired right up and seems to be fine now.

So something was up with the cop setup.
I checked continuity of the wiring harness with the wiring diagram and everything seems to be ok with proper connection to all the plugs with no shorts that I could detect.
Harness was grounded where the ECU grounds at the back of the intake.

I reached out to the seller who mentioned he had not had any issues with the harness but had a couple of customers with defective cops.
The seller without a question was willing to ship me out a replacement set.
This seemed too easy unless he was aware of an issue with this set?
It seems strange to me these would fail in such a short time frame.
I did not experience any misfires that I could tell it just would not start.
So I am guessing since this car uses a wasted spark setup and the cops have some kind of feedback signal that when one cop failed that maybe two coils wouldn't fire and car would not run?
I am curious to know which coil is bad to keep the good ones as spares.
Testing these without the proper equipment is easier said than done.
I may find a garage with a proper cop bench tester to see.
I suppose I could later start swapping back in the old cops to see which one causes the fault.
I did read of a 10,000uf capacitor being installed across 12v and ground as a filter but my kit did not come with this. Not sure if this is needed or not?
I guess I will see how the new set holds up.
Not sure if I need to do anything different moving forward or if I just had some bad luck.

Just thought I would share this experience.

92Yata

I was looking at these cops this morning and decided to do some measuring compared to the stock plug wire.
I believe the problem is the cop was not reaching down into the valve cover far enough to make good contact.
By removing the rubber washer on the cop allowed the cop to sit down 1/4" further making better contact with the spring to plug.
This would not be possible with the mounting plate that came with the kit as the stand offs would be to high.
I am using a different mounting plate that allows the cop to sit down further without the rubber washer.
With the mounting plate I am using I had needed to add some spacers to bolt them down. But without the rubber washer they sit down flush without the spacers.
It was obviously was making contact before as I ran them like this for a couple of months. I would guess they were just barley making contact and probably arcing. Just not enough spring compression.
I don't know if they are seated low enough yet but the car does start. I have not road tested yet but a 1/4" lower is quite a bit.

See attached photos.
I will update you if things change.
Cheers
J

The center plug is the stock plug wire and the outer is the cops with the rubber washer installed.








This is the mounting plate that came with the kit. These standoffs would be too high with the rubber washers removed from the cops.

xnano

Any update on this? Looks like the same cop kit I have. I can't get my car to run with the toyota cops anymore so I had to switch back to the stock system

92Yata

The solution for me was to remove the rubber washer from the COPs. This allows the cop to sit down further and make better contact with the plug. I put some dielectric grease around the sealing point to prevent moisture. I haven't had a problem since.

If you are using this aluminum plate with the standoffs you are going to either have to cut them 1/4" shorter or find some 1/4" shorter standoffs that will work with the rubber washer removed.

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rleete

iTrader: (21)

Because the kit is using off-the-shelf standoffs, it makes the plate sit too high. Either cut down the stand offs, or remove that rubber washer. I made my own, and cut the standoffs about 9/32 shorter than the store-bought ones.