I think my COP's are dead.
 

https://www.miataturbo.net/forum/t27811/

So if you guys remember that above thread.

I am still struggling to get to the bottom of it(next step im just gonna get an electromotive xdi). I checked my harness, checked the caps on the harness, changed my spark plugs(even though the ones in the engine were fine). Nothing left other then the COP's.

I had issues with these COP's from the very beginning, they never ran at 3.5/2.5 from day one. I had to run them at 4/3 to get the car to start and idle reliably. That was fine and dandy for about 6 months maybe more. I don't remember when I changed the dwell again but I have been running them at 4.5/4.5. Now its winter, and my car idles like total crap until the engine warms up. I am running the coils at 6/6 as of last night, and its actually slightly better. After the car is hot, I can actually reduce the dwell.

There's nothing else in my ignition system that could be the culprit.

I have another set of COP's on the way because im afraid of these dieing at any moment.

Has anyone ever heard anything as ridiculous as this? 6/6 dwell? How long do you guys think they will run?

junk them

I was thinking.

If I had a short somewhere in the wiring for the ignition the stumbling would be manifesting itself all the time.

More dwell can mean only two things, not enough voltage or dead coils.

Not enough voltage is probably not possible, but a short causing low voltage might be. Say if the 12v was hitting ground. But that would mean the fuses on the ignition would most likely blow.

Just stabbing in the dark here, new coils are on the way, but id like to think of other potential causes if it turns out to something other then coils.

you progressively increase dwell as your coils progressively become worse and worse :)


see the pattern?

I have bacially the same problem, It got to the point that I had to take a hair dryer to one of my coils to get it to run lol. I just got a new set.

Heres a question. have you tried unplugging the coils during the stumbling one at a time to check for a difference?

How fast did the idle really die down?

On my car, during the stumbling cold warmup, if I pull a coil, its like one one thousand, two one thousand, three one thousand and then the engine is chugging.

The car would only run on two cylinders. So I took a hair dryer to each coil intill it started, and it ended up being 2 bad coils.

Got new coils. same shit.

Put in new coils without touching anything, runs the same.
Put old coils back, change dwell to 6. Runs perfectly.
Put in new coils, dwell at 6, runs perfectly.
Change dwell back to 3 on new coils runs like shit, put in old coils, still runs like shit.

Yea, so its not the coils. I have no clue what the hell it is at this point.