I have 550cc RC Peak and Hold injectors in a 99 si with no resistor box. You can imagine....the car runs like crap and super rich. I picked up a resistor box the other day and I'm getting ready to wire it in. I notice that there is only 1 input wire and 4 output...maybe I don't understand how it works but it seems like to me with this wire in, every time 1 injector fires...all 4 would fire...which would waste a lot of gas. Just curious if this is the case or is injector timing controlled seperately??? Thanks for the help or any info....I have looked in the forums for this, but to no avail...thanks again.

 

That's right... one wire in (12 volts), 4 wires out (one for each injector).
The ECU grounds each injector to fire them.