Patent ID: 7089789

Claim:
A method for calibrating an integrated fuel injection system comprising the steps of: providing said integrated fuel injection system comprising an injection nozzle, an injection line, a cam follower including a tappet roller, a unit pump functionally connected to said injection line to deliver pulses of pressurized fuel through said injection line to said injection nozzle, and a fuel control arm radially projecting from said unit pump, wherein the timing of each said pulse relative to a rotating actuator acting on said tappet roller is dependent upon a distance between a bottom of said tappet roller and a lower surface of said unit pump mounting flange, and the volume of each said pulse is dependent upon an angular relationship between said fuel control arm and said unit pump; installing the integrated fuel injection system on a test stand comprising a rotating pump actuator, a flow meter arranged to measure a volume of each said pulse, and a sensor arranged to measure the timing of each said pulse relative to a pre-determined reference rotational position of said pump actuator; operating the integrated fuel injection system at a pre-determined actuator rotational speed and a pre-determined fixed position of the fuel control arm until performance of the fuel injection system is stabilized; measuring the volume of each said pulse at said pre-determined actuator rotational speed and at said pre-determined fixed position of the fuel control arm; when said measured volumes are not the same as a pre-specified volume then rotating said pump relative to said fixed fuel control arm until the measured volumes equal the pre-specified volume; fixing the rotational position of said pump relative to said injection line, injection nozzle and fixed fuel control arm; operating the fuel injection system at said pre-determined actuator rotational speed and a full fuel control arm position; measuring the timing of said pulse relative to the pre-determined reference rotational position of said pump actuator; when said measured timing is incorrect then adjusting the distance between the bottom of said tappet roller and the unit pump mounting flange lower surface to calibrate the timing of said pulse relative to said pre-determined reference rotational position of said pump actuator; and removing the integrated fuel injection system from the test stand as a calibrated, assembled unit to maintain the rotational position of the unit pump relative to the injection nozzle.