Electronically Controlled HEUI Injector Tester for CAT C7 C9 C3126 Unit Calibration

What is HEUI fuel injection system?

The HEUI system (Hydraulic Electronic Unit Injector) is a medium-pressure common rail, electronically controlled hydraulic injection system developed by C-aterpillar in the United States. Its core feature is the use of engine oil as the hydraulic medium, combined with electronic control and hydraulic actuation to achieve high-pressure fuel injection. ‌

Technical Features
‌Hydraulic Actuation‌: Medium-pressure (approximately 20-30 MPa) engine oil drives the booster piston inside the injector, raising fuel pressure to over 200 MPa. ‌

‌Electronic Control System‌: An electronic control unit precisely regulates hydraulic pressure and injection timing for precise injection. ‌

‌Independent Injectors‌: Each cylinder is equipped with an independent hydraulically controlled electronic injector, eliminating the traditional distributor structure. ‌

Comparison with Traditional Fuel Injection Systems
Unlike traditional high-pressure common rail systems (which rely on the inherent high pressure of the fuel), HEUI uses indirect hydraulic actuation, resulting in a more complex structure but higher fuel pressure. ‌

Unlike mechanical pump-injector systems, HEUI utilizes a combination of electronic control and hydraulic actuation to improve fuel efficiency and emissions. ‌