injector problem maybe?

[sen2two]

ok, so the fuel pump is brand new and i can hear it running (inline walbro 255). and i can actually hear the fuel running through the lines on the motor. also, i can see the fuel pumping back into the fuel cell. its in my trunk. so i know the fuel is getting through to everywhere... i swapped the primary injectors because i thought this was the problem. i "checked" them to see if they worked by putting a 12v source to one prong on the injector and grounding the other. i heard them click. so i figured they were good.

if my injectors are fine, and im getting fuel pumping just fine to everywere, what else could it be? ecu? air flow meter? something else?

i know the injectors are not firing because the spark plugs are brand new and i pulled them after cranking for a little, and they are still brand new. not a drop of fuel on them. also, i got it to start while spraying starting fluid...