Methods and systems are provided for conditioning fuel for diesel engine. The system may include a fuel pump located within a fuel tank configured to pump fuel to the diesel engine. The system may also include a fuel filter located outside of the fuel tank operatively located upstream of a flow of fuel from the fuel pump. A method may include directing fuel from inside of the fuel tank through a fuel filter located outside of the fuel tank into a vacuum chamber positioned inside the fuel tank, before directing the fuel to the diesel engine.