a fuel delivery system in an engine is provided with a fuel flow stabilizing device for instantaneously providing a precise amount of fuel to the engine according to a particular fuel demand . the fuel flow stabilizing device has an accumulator device which stores a reserve amount of fuel under pressure and supplies or accepts excess fuel in response to a change in fuel pressure in the fuel delivery system . the accumulator device allows a simpler fuel pump motor and control system to be used as fuel pump response time requirements are reduced .