You cant visually look at an injector and tell if its bad. You probably have some trash in it and its stuck open.
Are you running a proper fuel filter(s) for fuel injection? My bet is dirty fuel caused your problem, not a failed injector.
Could you just do a test with a gravity fed push of fuel (or something safer) and activation current applied to the injector? I cannot imagine that wiring one up would be all that difficult...just need the proper harness?
My thinking is: if the injector delivers fuel once activated than it must be something else that's causing the problem.
