I know all the miata MS users use inverted spark, but I just tried non-inverted for the heck of it and it runs pretty well. I didn't let it run long because the ignitor started getting hot. So, is something ***-backwards in my car? What should I check?

 

I changed the resistors on the LEDs to 330s, and now the car runs the same with inverted on or off - on one or two cylinders.

 

Are you only running on 2 cylinders?

 

What was the fix?

 

He had connected the spark output leads to the wrong side of the resistors.

It should be like this: https://www.miataturbo.net/forums/at...5&d=1148236634

I'm going to get some 1.8L coils to play with see if I can get them working right.