The 2004.5-2005 GM 6.6 LLY Duramax engine offered a fuel injector redesign over the failure prone LB7 injectors. The LLY injectors moved to a new externally mounted location (outside the valve cover), along with the fuel supply and return lines. This reduced the potential for fuel and oil dilution problems and also made servicing the injectors easier. GM continued to utilize Bosch for many of its fuel injection system components and control technology. This common rail injection system consisted of a low-pressure fuel system, and a high-pressure fuel system. The low-pressure side simply filters and transfers fuel from the tank to the injection pump, effectively keeping the injection pump lubricated and primed with fuel. The high-pressure side delivers fuel to the rails and injectors.
The LLY’s reprogrammed ECM (Engine Control Module) regulates the pump rail pressure by modulating opening/closing valves, regulators and actuators located on the pump and on the rail. Any excess fuel volume returns back to the fuel tank. Regardless of the application or make, rest assured that all common rail injection pumps have extremely precise internal tolerances and can be susceptible to damage if not provided with ample, well filtered, diesel fuel containing few contaminants. With each new iteration, the 6.6 Duramax, and its updated injection system has given Duramax enthusiasts more confidence, performance, and reliability than previous fuel systems, and the control systems within the ECM can now deliver significant power while metering the fuel more precisely than ever.
Whether you are looking to perform routine maintenance with a GM fuel filter, repair your fuel system with high quality XDP, Industrial Injection, or Alliant parts, or improve your fuel system with an upgraded Lift Pump, or step-up performance and reliability with a Dual Fueler kit, Ported Fuel Rail Fitting or Race Valve, XDP has your 6.6 Duramax LLY Fuel System covered. In addition, XDP offers stock replacement parts such as Bosch CP3 Pumps, Fuel Injectors, Fuel Lines, as well as fuel system gaskets and seals. XDP carries LLY Duramax parts from all the leading manufacturers like Bosch, Fleece, S&S Diesel, GM, FASS, AirDog, PurePower, Dynomite Diesel, Bostech, DTech, and more.
