OK, I feel really dumb asking this question(First nonpiston car). Why do we have leading and trailing plugs? How do they fire? One on new fuel/air mixture(lleading) and once more on already burnt fuel? Or another way? The reason is I just had a recall performed and only leading plugs were replaced. I only read the invoice when I got home.

 

You basically have the idea down about the leading and trailing plugs. Why was the leading replaced? Without seeing the recall it only becomes speculation but for starters, the leading plug fires twice during the ignition sequence while the trailing only fires once. Maybe there was an issue with the reliability of the leading plug.

Of course, always consult the mighty Google as well (homage to MUGATU )
Here are a few sites that I dug up:
http://www.silverbulletrx7.com/plugs/
http://www.rotaryengineillustrated.c...-ignition.html

Cheers

 

Voluntary Eission Recall R4206F
Inculdes cat inspection and test. Replace leading plugs. Reprogram PCM new ca: N3ZA-18881-H

 

first coil goes to the 1st rotor leading plug.. the lower one...
second coil goes to the 1st rotor trailing plug.. the upper one.

all from the front of the car to the back..

repeat for the 3 and 4th coil..

beers

 

The trailing does a LOT more than "clean up" the combustion process.

 

I thought there was 4 separate signals now for the Renesis setup so therefore the trailing plugs do not fire a waste spark anymore?

That and I thought I read somewhere that during idle rpm's or so the trailing actually precedes the leading for a better combustion?

 

Yes.