I am not getting any spark from the trailing coils. It will fire really weak for a second at start up but as soon as the engine catches it stops spark. The ECU is fucked. I put in my friends 88 ECU in my car and the idel problem went away the trailing coils are getting beautiful spark, and i took it for a test drive and omg that pep it once had is back. I could even connect my pressure sensor and it wont flood. I need an ECU any one got a spare S4 ECU?

Right here man! N326 with your name on it!

If youre trailing coils werent firing, youre tach wouldnt work.

Aside from that, trailing coils are there for emissions. They serve no real purpose in making power or holding a steady idle.

Ever seen the inside of a rotor housing? The leading sprak hole looks like this -> O and the trailing spark hole looks like this -> .

I drove my car for a long time with no trailing spark and it didnt cause ANY drivability issues.



I think youre real problem lies somewhere else.

Glad to hear it man...

yeah for a while my trailings werent working and my tach would go off. no driveability probs though

thats understandable, but if using his buddie's ECU fixed his problem, then I guess he already said where the problem lies. The trailing coil issue is just secondary. maybe he meant the leading coils?



Anyway, glad to hear you've figured it out, hope you fix it soon.

If his leading coikl wasn't firing and only the trailings were, he would know it. When mine was doing that I couldnt get it up much past 3k.

My leading is firing but the spark sucks and the trailing is not firing at all. Mabey the trailing coil not firing may not cause driveability issues but if the ECU is fucked it would. And I think that the trailing coil is there to complete the combustion process but I could be wronge.



I have seen the L & T holes and there is a big size diffrence. Im telling you guys after i put on his ECU it felt like a brand new car. When I get the ECU im gonna put in a CraneCams HI6 Ignition to help out. https://www.nopistons.com/forums/pub...1047683473.gif

You would be wrong about that. Its for emissions. Just to clean up the tail end of unburnt hydrocarbons.



Also, Im not saying the ECU didnt fix your problem, and Im not telling you NOT to get a new one. All Im saying is if youre trailing plugs arent firing, youll have no tach ( Is your tach working? ). And I dont think that youre car is running crappy because of no trailing spark. Thats all.

Trailing plugs do help complete the combustion. THey do add a very small ammount of extra power per stroke. And they do definately make the car run smoother (i'm guessing their main purpose)