It sounds like all your injectors fire at once, common on older systems. In my car I have two injector fuses, one for each bank of cylinders. I have made a 3 cylinder Fiero but it was terrible to drive! Thats where I wired my injector kill switch for EOC, I never tried to kill just one bank at cruise speed! I could wire it to kill one bank for cruise at speed but It's really hot here now
