Abstract: An apparatus for cleaning an electronic fuel injector having an inlet and an outlet wherein the fuel injector is supported in an ultrasonic bath of cleaning fluid such that at least the outlet tip of the fuel injector is immersed in the fluid while the bath is resonated with ultrasonic energy. The fuel injector is pulsed by an electrical signal, the combination of the ultrasonic resonance and pulsing action causing the fluid to flow through the fuel injector from the outlet tip to the inlet.

Abstract: A method of cleaning an electronic fuel injector having an inlet and an outlet, comprising the steps of supporting an electronic fuel injector in an ultrasonic bath of cleaning fluid such that at least the outlet tip is immersed in the fluid, resonating said bath at a frequency between 1.0 and 50 kH.sub.z and pulsing said injector between 1.0 and 40 msec at a R.P.M. of between 50 and 15,000, whereby the cleaning fluid, while being resonated by the ultrasonics, flows in a reverse direction from said bath into the injector outlet, through said injector, and out of the injector inlet, as a result of the interaction of the ultrasonics and said pulsing of said injector.