These are Bosch injectors and are usually extremely reliable unlike the Siemens/Deka they used previously, there is one possible issue with these and that is some did not have filters installed and no provision to install them after the fact.It's been good until now. Somehow I have a dead fuel injector on cylinder 1. It was full of fuel. Checked everything including wiring. Took everything off again and reassembled to make sure it was right. One step forward and two steps back as usual.
Make sure the rail(s) is spotless inside clean outside and any inline filter has been replaced and the line blown through. Anything in the line or rail will get into an injector(s) and can cause them to flow poorly or stick open or closed.
Check the ohms of the injector and voltage at the connector with a dvom or use a noid light. I install injectors with vaseline or WD40 on the o rings, both work very well and cause no difficulties when removing them, the silicone grease tends to turn into a white powdery substance making removal after a long time sometimes very difficult.
Tip. When removing injectors spray some WD40 where the o rings are and turn the injector back and forth slightly before pulling it.