Both coil packs fire at what RPM?

[PetesPonies]

Trust us . . what Earl and I are saying is correct.

 

[Mikel89us]

Maybe i am wrong about only one firing at idle, but i do know that only one coil pack fires under high RPM heavy loads.

 

[cbeck]

I heard a rumor that the second plug fired on the ehaust stroke for emissions, again a rumor i heard from my kid. he has a associates degree from rankin plus ase enginesplus engine wiring

 

[PetesPonies]

Both plugs fire on an exhaust stroke. That's why it's called a wasted spark ignition. But a wasted spark ignition has nothing to do with a 2nd spark plug. Anytime a coil is shared by two cylinders, you will have a wasted spark. Motorcycles have been doing this for over 40 years.The second plus us there to fire nano seconds after the first spark to create better combustion. And this is why bad information gets passed along and people start believing it. So your son is wrong. Sorry. Or . . you are misunderstanding what your son is saying. Because mixing terms "wasted spark" and "twin plugs" confuses people. It sounds like info from one term relates to the other, but they are completely different; completely.What am I?? a retired Auto teacher.