Ive asked a few freinds and searched but cant figure out what exaclty it does.

 

ECU tells ignitor when to fire coils.

 

why doesnt ECU just tell coils when to fire

 

prolly cause the ECU can't drive the coils directly (not enough voltage/energy -- not a question of timing), so the ignitor is basically an amplifier (thus must have it's own power connection)... or possibly, the ECU is just a trigger for the ignitor (I would have to look at the internals of the ignitor)

 

The triggers tell the ECU where the crank is, the ECU tells the ignitor to fire the coils .

 

SO even when running aftermarket Igniton amps,and coils you still need the ignitor than?

 

the ignitor also kepps the ecu safe from any voltage spike from the coils.

 

yes