Fuel Related | 2011-2016 GM 6.6 Duramax LML
Beginning in model year 2011, GM made some big changes to the Duramax's fuel system. One of the big kickers was the replacement of the long standing, tried and true CP3 injection pump in favor of a lo ... read more
Beginning in model year 2011, GM made some big changes to the Duramax's fuel system. One of the big kickers was the replacement of the long standing, tried and true CP3 injection pump in favor of a lower output CP4. This move was derived from their move from the traditional common rail fuel injectors to piezo injectors that technically require less fuel. While we agree that piezo injectors are more efficient than their predecessor, the move to a CP4 has proven to be a bad decision as countless failures have been recorded even on stock trucks, let alone modified trucks that require higher than stock levels of fueling.
Now, compound all of this with the fact that Duramax's have NEVER had a low pressure lift pump supplying fuel to the injection pump and you have some serious room for improvement. We have found that by adding an in line fuel pump will drastically increase the life of the CP4, also allowing those who are adding additional fueling through chips/programmers to realize the full potential of their power. We carry systems from both Pureflow and FASS that will help maintain proper fueling. Both of these systems allow you to choose either a stand alone pump, or a pump with fuel filters and water separators which removes entrained air, reducing the chance of injector failure. And if you'd like to eliminate the failure prone CP4 in favor of a CP3, we offer conversion kits to get the job done to deliver reliability and performance.
Overall, the LML's fuel system has a ton of potential, it just needs some assistance from the aftermarket to made it unstoppable. As always, if you are having any issues determining the right parts for you and your truck, do not hesitate to give us a call or send an e-mail to [email protected] and we would be happy to assist.