An injector model built with the platform LMS Imagine.Lab AMESim has been introduced as a useful tool used in one of the practical lessons taught in the "Mixing formation and combustion systems in the Reciprocating Internal Combustion Engines" course. This course carries 6 ECTS and is a first year course in the second semester of the Master's in "Reciprocating Internal Combustion Engines". Using a standard model that has been previously implemented and validated, the students have to carry out an analysis of the injection process from the point of view of the operation of a modern solenoid-valve operated injector. The goal pursued in the lesson described here is, on the one hand, to help the students to understand how injectors work from the moment when they receive the current from the ECU of the engine up to when the fuel is delivered to the combustion chamber as a diesel spray. The different mechanisms involved will be analyzed by the students by exploring important internal variables, such as pressure variations, moving part displacement and, in overall terms, all the variables involved in the injection phenomenon. On the other hand, the students will be able to identify the critical parameters that play a major role, affecting the mass flow rate to a greater extent, by analyzing the response of the system under different geometrical configurations and different operating conditions. There is some evidence that the new teaching approach significantly improves the learning process when compared with the previous teaching methodology.