Big job to roll injectors on CSFI, need to remove the entire injector assembly and disassemble it. Also, you can't access them with the engine running to check for clicking sound. Not even sure if you could safely swap wiring without damaging the connector. Checking fuel pressure isn't a bad idea but, a leakdown test will tell if an injector is stuck open, and an injector balance test will tell if it's stuck closed. You can also check the wires to the injector for power and pulse, but you'll need a noid light to test for pulse. You can use a test light to check for battery voltage at the injector, it's a pink wire. Don't use the test light on the ground circuits at the injector pack, it can damage the driver in the PCM, you need to use the noid light to test for ground pulse.