GM Introduced Gasoline Direct Injection (GDI) on the Gen V LT Platform where fuel is injected directly into the combustion chamber like a diesel instead of into the intake runners (often referred to as Port Fuel Injection) in previous generation engines. GM used different High Pressure Fuel Pumps (HPFP), injectors, and fuel rail pressure sensors across different years and applications of Gen V LT. Components must be matched for proper functionality and performance.

Fuel Rail Pressure Sensor

Fuel rail pressure sensors had early and late designs where "early" 2014-2016 used a 4-wire analog sensor and "late" 2017+ used a 3-wire digital sensor. Your sensor and harness must match.

High Pressure Fuel Pump

The HPFP had early and late 2-wire electrical connectors as well, with "early" being 2014-2018 and "late" in 2019+ except for the LT4 pump that kept the early connector throughout. If you are swapping an LT4 pump into a "late" platform vehicle, ICT Billet PN WAFP050-6 can be used to adapt your harness to the early style connector on that pump.

The LT4 high pressure fuel system operates at a higher pressure than all other Gen V systems. It is strongly recommended to match LT4 injectors when upgrading to an LT4 high pressure fuel pump.

Injectors

The injector lower stem diameter changed on a rolling basis from 2021 through 2024. Early injectors had 7.5mm stem diameter while late injectors had 6mm stem diameter. Vehicles produced in 2021-2024 may have used either stem diameter and must be measured if you are replacing injectors to ensure proper fitment into cylinder heads. All LT injectors use USCAR EV6 connectors.

Low Pressure Fuel System

The low pressure fuel system that supplies fuel to the high pressure pump operates at 5 bar (72psi) in Gen V LT vehicles.