Since you got that far then just swap the suspected bad injector with the one next to it and try it. The problem will either follow the injector or it will stay with the throttle bore. If the problem stays with the throttle bore then you have a wiring or circuit board problem. If the problem follows the injector then you have a bad injector. If the problem goes away then you have something else going on. Once you do the swap test you'll have a much better idea of what the actual problem is.