An assembly is disclosed having a high pressure fuel source, a low pressure fuel source, and a housing. The assembly also has a piston disposed within the housing and dividing the housing into a first chamber, a second chamber, a third chamber, and a fourth chamber. The first and second chambers are fluidly connected to the high pressure fuel source. The third chamber is selectively fluidly connected to the high pressure fuel source and the low pressure fuel source, and the fourth chamber is fluidly connected to the low pressure fuel source. The piston is movable from a first position when the third chamber is selectively connected to the high pressure fuel source. The piston is movable to a second position when the third chamber is selectively connected to the low pressure fuel source.
