Injector signal wires?

Hello, while Im pulling up the wiring harness diagrams, is Cylinder #4 the only cylinder setting a misfire code? No other codes or warning lamps at all?

Have you had a chance to load test the power wire to the #4 injector yet? If you have not checked that yet, theres a better test, check for 12volts on the #4 injector control wire with the key On at the ECM connector. this way you are testing 2 circuits at once. You should read 12volts on the injector control wire until the ECM starts to ground and activate that injector which it wont do until you start to crank it. Reading 12volts means the ciruit, so far, seems to be intact with power coming from a fuse through the injector and you will read it at the ECM connector just sitting there waiting to be commanded on. Im getting the ECM pinouts right now

Here are the two ECM connector pinouts, the wire you are looking for is in connector C2, pin 75 LightBlue/Black wire (circuit 844) should read 12volts when back probing the C2 pin 75 wire coming through the injector. If its low or seems to be searching a lot for a stable voltage with the key On, then I would load test the power and control independent of each other. Hopefully this is making sense, its getting late and been a very long day. but please let us know what the fault turns out to be, it helps others.