An injector for injecting a fluid from a syringe (which syringe includes a body, a plunger moveably positioned within the body, and an encoding device providing syringe information)r includes a housing, a motor disposed within the housing, a controller operably associated with the motor, a sensor operably associated with the controller and operable to read the encoded syringe information provided by the encoding device when the syringe is attached to the injector, a drive member disposed in the housing and powered by the motor, the drive member operable to automatically advance and engage the plunger when the sensor reads the syringe information provided by the encoding device, and a plunger engagement detection device operably associated with the controller and operable to indicate when the drive member of the injector has engaged the plunger of the syringe.