Abstract: Disclosed herein is a fluid-actuated, diaphragm pump which is particularly adaptable for use as a fuel pump for a multi-cylinder, two-cycle internal combustion engine and which includes an inlet chamber, an outlet chamber, a first diaphragm separating the inlet chamber into a first pulse chamber and a suction chamber, and a second diaphragm separating the outlet chamber into a second pulse chamber and a pressure chamber. The two pulse chambers are connected to separate sources of regularly cycling or pulsating pressures which are at least 90.degree. out of phase from each other and the two diaphragms are oscillated sequentially, in response to the pressure variations in the respective pulse chambers, between a suction position and a pumping position whereby fluid is first drawn into the suction chamber through an inlet, subsequently pumped therefrom into the pressure chamber, and then pumped from the pressure chamber through an outlet.