We need more info here.
Hmm...most EFI's have ignition drivers built-in. Is there a special reason why you want to run it trough ignitor? What EFI and does it have the driver circuitry built in?
Also, what kind of ignition system do you use? Singe-plug? Dual plug? Six independent coils? Twelve independen coils? Six dual coils with one coil per cylinder? Six dual coils MUX-ed?
1. getting rid of ignitiors annd using built-in circuitry (if such exists in EFI)
2. using six dual coils in multiplexed manner (on twin-plug engine).
You ignitors are probably feeding too much current into the coils or your saturation #'s are out of tune.
Thank you for your time,