Mini the injector is not as bad as it seems to change out. How did you realize the injector was bad? I suggest before you replace the injector go the local dealership i ask for a fuel injector service it is a pressurized can of cleaner you have to take the fuel pump loose and tie it into the line. It done wonders on my 3.4 but only problem is the tool to it is a dealer tool. Don't seem to  sound like a jerk but are you sure you actually working on cyl. 3. I've seen alot guys get the cylinders mixed up.