1986 Chevy Astro with 4.3 engine--no electricity at fuel I

Electrical problem
1986 Chevy Astro 6 cyl Two Wheel Drive Automatic 150k miles

There isn't any electricity at the fuel injectors? I have checked all fuses- they are good. I have also replaced fuel pump relay and ignition control module. Oh and also replaced fuel pump. I also have put a used ecm/computer in van. Still there isn't any spark at injectors? Should both sides of injector be hot? Can you help me out with any ideas? Thanks