Diesel fuel injector tuning tool

Abstract

A tool for tuning an engine having a fuel injector unit with a follower and a body with a flange portion protruding outward from the body, includes a support structure having a follower contact surface, a plunger member slidably connected to the support structure, for bearing against the flange portion, a light source connected to a power source, a circuit for delivering electric current from the power source to the light source, and a switch which closes the circuit when the plunger member is moved to a predetermined position, and opens the circuit when the plunger member moves out of the predetermined position. The support structure preferably includes a tubular housing having two ends and which receives the plunger member in one end. A spring is preferably provided for biasing the plunger member in an extended position relative to the support structure. The follower contact surface preferably includes an outward projecting arm member, including a plate having a recess for receiving the top of the follower. A method is provided for tuning a fuel injector having a follower and a body portion and a flange protruding from the body portion, using the above-described tool, including the steps of placing the plunger member against the flange, positioning the arm member over the follower, moving the support structure toward the flange until the arm member touches the follower, and observing whether the light source becomes activated.

Dependencies are inferred from the claim text.