The easiest way I've done it on other makes is first test the fuel pressure and volume. If it's within what the manual states, then I leave the fuel line and electric connected to the injector and pull it. Then turn the key on to let the pump pressure up. If the injector shows no sign of leaking I turn it over and watch for the fuel pulse spray. If it does and its nice and even..and strong, I re-assemble and test the other one. If for some reason there is no pulse, then I test the CPS...aka engine speed sensor. If it passes then I look to the ECU.
If I find one that leaks with just the key on, it gets replaced along with the fuel filter.