I have a series III rx7 12a. I have no trailing spark at all, leading spark is fine. I know the trailing spark is surpposed to engage when engine is under a load or choke is applied and when in 4th or 5th gear. But I'm getting no sparks at any of these events. Swapped trailing coil over with leading coil the trailing coil works, so both of the coils are operative, leads are fine and plugs as well, cleaned electric dissy contacts set timing but could only set leading timing of course. Its really starting to frustrate me. If anyone has any ideas or fixes would be highly appreciated.

 

Does your tach work? What about your fuel pump? If its your Trailing ignitor neither of these would work...

 

my tach works fine my coils work fine both ignitor modulators on the side of the dizzy work i know this cause i swapped conponents from trailing to leading and all the components work when they are applied to the leading. My question is how do i test the trailing spark and is there a relay or wire that plays up with age. Thanks for your reply too. Cheers Jay

 

If you don't know how to test the trailing spark, then how do you know it's not working?

If your tach is working, then the ignitor is firing, so it must be between the ignitor and plug (coil, distributor, wiring, or the plugs themselves)

 

to check that they are getting spark use a timing light.... Either that or take a plug right out and get someone to crank the engine when you have a plug close to a piece of metal and note if you can see the spark jump (don't get electrocuted...)