My car started and ran first crank after making the Dwell change in my MS. This is proof that God Loves me! The car ran, and I sat their amazed I've been working on the wiring since 1pm today. I followed the diagram below for a 1.6 running a MS. with the exception of running two 4700's rather than 1 10,000 similar to Joe's example.

https://www.miataturbo.net/forum/t12704/

After a minute, of super smooth running I heard pop sizzle, Pop Sizzle, and saw smoke. I turned off the car, because it was still running as nice as it did when it started, and saw smoke coming from the capacitors. The caps are running in parallel in the same location as the single 10,000 in the diagram. Would me moving them have caused this issue.

And what liquid is the liquid in the cap toxic or corrosive?

 

It's an electroytic fluid, and usually contains some boric acid. It can be corrosive, but nothing really serious. I would definitely wash hands, wipe down harness, and consider re-wiring if wire casings seem brittle.

I hope you figure out what made them pop, I plan on doing the same mod in near future.

 

+1, Fish oil!

 

that can happen if you install the caps backwards. Are you using polarized caps? If I'm not mistaken though, the caps aren't really needed if you're running a MS. I thought they were only used as a band-aid for the stock ecu. I don't run caps on my 97, and I run a .06 spark gap.

 

You dont need caps, throw them out.

Did you perform the resistor mod on your megasquirt?


Why the **** would you run .06 spark gap?

 

Because it translates into more spark energy which adds more energy to the cylinder during the combustion process. More energy = more Pdv work. The spark energy could be up to say .01 Joules of energy. Granted, the amount of energy released by the fuel is probably 1000 kJ, so it's on the magnitude of a .01/1000000 level or 0.000000001% increase in total energy into the cylinder, of which ~15% of that would be turned into useful work. So about a .0000000000000015% increase in HP easy. Why not? Oh but if it ever missfired from too much gap, you'd loose enough energy that it would take (1000000/3)/.00000000000000015 = huge number of cycles before you got back to normal....

 

The caps ensure all the power is at the coils....just like you would install a 1-fraud Cap for a large amplifier pounding some bass.

Sounds like you reversed the polarity....

 

If I can remove the caps I'll do it tonight and be running COP today, if I need the caps, I'll get two more this week from radioshack and redo the harness this weekend. Braineack you listed them in your writeup, are they required.

I did install the resistor for the MS, to my surprise after the caps popped the car seems to have run fine. Maybe better than it has been running on the stock system.

BTW when I go in for inspection, or when I check timing with a time light, do I use the harness connected to the first COP as I did with the factory ignition system, or is there some other procedure, considering I don't have plug wires any longer.

I wasn't 100% on the polarity, so I used the arrows as an indicator, the top leads are going to the 12v and the bottom leads connect to ground.

 

It is rumored that some timing guns will function in a COP configuration if you attach the clamp around the ground wire. Personally, I kept one of my old plug wires, and I unbolt the #1 coil, jam the plug wire up into it, and then put the other end on the plug.

Like I said in my response to your PM, it really sounds like you got the polarity backwards on these. On the plus side, we blow 'em up all the time in the lab, and the contents of modern electrolytics (unlike the older paper versions) seem to be relatively benign. Technically, yes, they are both toxic and corrosive. But you're not gonna just drop dead immediately if one goes off in front of you.

 

I need to remove the resistor from the diagram....you only need it if you're standalone. I didn't draw the diagrams. Plus I find it easier/better to install it in the diagnostics connector on IG- to B+.


My inductive pickup works around the wiring to the coil, as well as three different dynos I've been on.

 

I haven't tried this myself- probably should at some point.

Do you fish out the (-) wire, of just clamp onto the whole bundle?

 

First dyno i went to wanted just the trigger wire and used that. Any other time I just pull the wire loom back and clamp over all four wires.

 

I had to read that like 3 times to get the sarcasm.

To be totally honest and I know this is off topic. I think the COP conversion is all together useless, especially now. Why? Because I think our spark blow out issues are the cause of not weak stock coils, but because of having the wrong pull up resistor on the spark trigger. It makes sense too, spark blow out occurs at high rpm's, high boost. Why? Weak spark. What caused the weak spark at high RPM's? The wrong pull up, and something increasing too much. Joe Perez and Matt Cramer both explained it.

 

It's just as useful as a dual feed rail, yellow split tubing over your vacuum hoses, painted valve covers, and oil shedding coatings on the bottom of the pistons. (for crying out loud, if you don't want oil on the pistons, remove the factory squirter's pointing at them!)

Some people say they have spark blowout running stock gap with high boost and a MS 1. As you mention, it helps to fully charge the coil. I just run less gap and it works fine for me. Actually, I'm running EDIS ignition so I use that stock coil. But it too works fine with a plug gap of .020". No spark problems to report.

 

i use cops because they're
-cheaper than a stock coilpack
- more durable
- you don't have to replace wires. Also if you do ever blow one, its usually just one. stock coils, you have to throw the whole thing out. But that's already been beaten to a pulp. I have no issues with my huge spark gap though. I'll lower it back down when its time to replace them, but eh, seems a little smoother on the revs to me.

 

The cap has nothing to do with the MS. You are mistaken.

 

COPs are cool.

There, I said it.

If, given the "wrong" pullup resistor, COPs provide a more reliable spark than stock coils for a given gap and set of operating conditions, then with the "correct" pullup, the COPs should be capable of running with larger gaps than stock coils. (regardless of what the label says, the actual voltage produced by the coil is almost entirely a function of how large the gap is. During discharge, the voltage potential builds up in the secondary until it's high enough to cross the gap. Once the arc begins, the voltage does not grow any higher. So larger gap = higher voltage spark.)

After the COP conversion, I started opening my plugs up from .020" in small increments. I stopped when I got to .045", because it was starting to get ridiculous. At that gap, I have zero ignition problems even when hitting 15-16 PSI on rare occasion.

But more than anything, they're just cool. That, and the fact that they don't take up space at the back of the head makes reaching behind easier when I need to access something back there.

 

I took a look at my car and harness when I went home for lunch. The caps are indeed backwards. I'll replace them this week, and get everything back in place.

 

It also says something when do gap to .045" and are able to remove gobs of fuel from your map....more complete burn ftw.

 

+1
I experienced this a TON after switching my old plugs out with my high gap ones, but it was probably a good bit due to the fact that my old plugs were pretty old.

Edit: oh and