HYDRAULIC AR 4223264 - Caterpillar

Illustration 1 g06201640
(1) Solenoid
(2) O-ring
(3) O-ring
(4) Fuel supply inlet
(5) O-ring
(6) Fuel injector nozzleThe common rail fuel system on this engine utilizes electronically controlled fuel injectors. This system uses an electronically actuated solenoid (1) to control the injection of fuel into the combustion chamber.Pressurized fuel from the accumulator quill tube enters the injector fuel supply inlet (4). Fuel injection occurs when the injector solenoid is energized by the Electronic Control Module (ECM). As the solenoid is energized, a magnetic force is generated. This magnetic force opens an internal control valve which drains the pressure acting on top of the nozzles internal check valve. The pressurized fuel lifts the check allowing high-pressure fuel to be injected into the combustion chamber. Fuel is discharged through orifices in the tip of the injector. The atomized fuel is injected into the combustion chamber.The fuel injector is cooled by fuel which is routed through the engine cylinder head. Low-pressure cooling fuel enters the injector between O-rings (2) and (3). Low-pressure cooling fuel exits with internal leakage fuel between the bottom O-rings (3) and (5).
Illustration 2 g06201679
(6) Fuel injector nozzleThe tip of fuel injector nozzle (6) protrudes for a short distance below the cylinder head into the combustion chamber as shown in Illustration 2.The injector also utilizes electronic trim (E-trim) to help reduce injector-to-injector variability. There is a unique E-trim file that is generated for every injector and is identified using the injector serial number. After the installation of an injector, the corresponding E-Trim file will need to be loaded in the ECM to ensure proper operation of the injector.