A fuel pump for a fuel supply system having some injectors supplied by a pressurized common rail and other injectors supplied through inlet ports, and an electronic control unit, said fuel pump comprising: a feed passage with inlet check valve; a pumping plunger reciprocable in a pumping chamber that is fluidly connected to the feed passage downstream of the inlet check valve, for pressurizing the feed of fuel; a discharge passage from the pumping chamber for delivering pressurized fuel to a first outlet check valve; a direct injection passage extending through the first outlet check valve for fluid connection of the pump to a common rail; an auxiliary passage in fluid communication with the discharge passage upstream of the first outlet check valve; a control valve having an inlet side in fluid communication with the auxiliary passage and an outlet side, wherein the control valve selectively closes against flow through the control valve or opens to permit flow through the outlet side of control valve; and a port injection passage from the outlet side of the control valve for fluid connection of the pump to an inlet port on individual injectors, through a second outlet check valve, characterized in that the pumping plunger has a charging stroke and a pumping stroke, and the opening or closing of the control valve is responsive to a signal from the electronic control unit corresponding to the position of the plunger during the pumping stroke during the charging stroke the pumping chamber fills with fuel to a maximum volume; during a first portion of the pumping stroke the control valve is closed and a first quantity of fuel is pumped through the first outlet check valve, corresponding to a first portion of the maximum volume; and during a second portion of the pumping stroke the control valve is open and a second quantity of fuel is pumped through the second outlet check valve, corresponding to a second portion of fuel consisting of all the fuel remaining in the pumping chamber; or during a first portion of the pumping stroke the control valve is open and a first quantity of fuel is pumped through the second outlet check valve, corresponding to a first portion of the maximum volume; and during a second portion of the pumping stroke the control valve is closed and a second quantity of fuel is pumped through the first outlet check valve, corresponding to a second portion of fuel consisting of all the fuel remaining in the pumping chamber. a feed passage with inlet check valve; a pumping plunger reciprocable in a pumping chamber that is fluidly connected to the feed passage downstream of the inlet check valve, for pressurizing the feed of fuel; a discharge passage from the pumping chamber for delivering pressurized fuel to a first outlet check valve; a direct injection passage extending through the first outlet check valve for fluid connection of the pump to a common rail; an auxiliary passage in fluid communication with the discharge passage upstream of the first outlet check valve; a control valve having an inlet side in fluid communication with the auxiliary passage and an outlet side, wherein the control valve selectively closes against flow through the control valve or opens to permit flow through the outlet side of control valve; and a port injection passage from the outlet side of the control valve for fluid connection of the pump to an inlet port on individual injectors, through a second outlet check valve, characterized in that the pumping plunger has a charging stroke and a pumping stroke, and the opening or closing of the control valve is responsive to a signal from the electronic control unit corresponding to the position of the plunger during the pumping stroke during the charging stroke the pumping chamber fills with fuel to a maximum volume; during a first portion of the pumping stroke the control valve is closed and a first quantity of fuel is pumped through the first outlet check valve, corresponding to a first portion of the maximum volume; and during a second portion of the pumping stroke the control valve is open and a second quantity of fuel is pumped through the second outlet check valve, corresponding to a second portion of fuel consisting of all the fuel remaining in the pumping chamber; or during a first portion of the pumping stroke the control valve is open and a first quantity of fuel is pumped through the second outlet check valve, corresponding to a first portion of the maximum volume; and during a second portion of the pumping stroke the control valve is closed and a second quantity of fuel is pumped through the first outlet check valve, corresponding to a second portion of fuel consisting of all the fuel remaining in the pumping chamber.