what are trailing coils and how do they work?

 

The trailing coil(s) and trailing ignition system are simply another ignition system, right along side the regular(leading) ignition system.On the old school rotaries,there were actually two distributors,two totally seperate systems.On the later engines,they combined the function of the leading and trailing timing into one distributor or crank angle sensor.There are still 2 independant leading and trailing coils,because they are firing their plugs at different times.1st gens have 1 trailing coil and the distributor cap handles the routing of the spark.The 2nd gen has two trailing coils,which fire their own individual sparkplugs directly.
It works the same way,and does the same things as the primary igntion......except that the trailing spark happens later than the leading spark.By firing the trailing sparkplugs after the leading,those plugs will ignite the portion of fuel/air mix that collects in the back of the rotaries combustion chamber.Its mostly for smog control,and the engine will run almost the same if the trailing plugs stopped working.
In a sense,its kinda a redundant ignition system,which can be nice if one of the two systems fails(as they often do on 1st gens) The engine might run badly or be lacking power depending on which of the two systems fails,but at least youll be able to cruise or limp home.

 

As Steve has stated the trailing is mainly to clean up emissions with it only adding to approx 2% of the engines output which would barely be missed.

 

O thanx for the info and umm if you can post any pics that would help me understand more about it that would be cool thanks

 

Well...........

If you understand how a regular ignition system works,then you already understand how the trailing system works.Like I said,they are identical except that the trailing fires its sparkplugs a little later than the leading.
The only odd part compared to a regular piston engine ignition system, is the distributor rotor. On a 1st gen engine,the distributor rotor has 2 seperate sections.One distributes the "spark" from the leading coil and the other distributes the "spark" from the trailing coil.Its basically a way to have 2 distributor caps(like the dual system of the old school rotaries),within one distributor cap.
If you dont understand how a conventional piston engine ignition system works,there are many websites that explain it in detail.....

http://auto.howstuffworks.com/ignition-system.htm

 

I get it thanx a lot and my Rpm gauge dose not work coud that be a problem with the trailing coil or the distributer

 

Rpm gauge ? You mean tachometer ? How old are you, elijah ? Can you spell booster seat ?

 

The tach does get its signal from the trailing coil.
If the trailing ignitor,trailing dist. pickup sensor or trailing coil fails,then you will not have any RPM indication.