a first step would be to identify the injector you have.
Which Kind of loco do you have? (RL1, MD, ...)
Is it fitted with the original engine?
In this case you can find the user manuals (often helpful) on this page: Feldbahnseite
If you need further help, please just ask. There are a few People here that could help you with further information.
Have a nice sunday, Benedikt