If either injector wire is damaged, it could be causing the fault. Check both wires for open circuits and shorting to ground or shorting to each other. One way to rule out a wiring fault would be to cut the injector wires (RED and YELLOW I believe)
near the COMPUTER, and near the injector, and then run two new wires in their place, connecting the new wires to the old leftover ends with a soldered and weatherproofed splice. This would not resolve an issue with the wire terminals however, so keep in mind to check for problems with poor crimps, broken wiring at the connectors, and loose terminal fit onto pins of computer and injector.
I would suggest using a NOID light for testing the injector signal, connect it to the cut injector wires near the computer right after cutting and see if there is a signal before running the new wires.
