An injector comprising: an injector body including- a base portion configured to receive a first fuel and at least one of a second fuel and a coolant into the body; and a nozzle portion coupled to the base portion, wherein the nozzle portion is configured to be positioned proximate to a combustion chamber for injecting the first fuel and at least one of the second fuel and the coolant into the combustion chamber; a valve seal positioned at or proximate to the nozzle portion; an ignition rod extending from the base portion to the nozzle portion; a valve coaxially disposed over at least a portion of the ignition rod, wherein the valve includes a sealing head and moves between an open position in which the sealing head is spaced apart from the valve seal, and a closed position in which the sealing head at least partially contacts the valve seal; a first flow channel extending longitudinally through a center portion of the ignition rod, wherein the first flow channel is configured to deliver the first fuel to the nozzle portion; a second flow channel fluidly separated from the first flow channel and extending longitudinally through the body adjacent to the valve, wherein the second flow channel is configured to deliver at least one of the second fuel and the coolant to the nozzle portion; a first coupling fluidly coupled to the first flow channel to deliver the first fuel to the first flow channel; and a second coupling fluidly coupled to the second flow channel to deliver at least one of the second fuel and the coolant to the second flow channel. an injector body including- a base portion configured to receive a first fuel and at least one of a second fuel and a coolant into the body; and a nozzle portion coupled to the base portion, wherein the nozzle portion is configured to be positioned proximate to a combustion chamber for injecting the first fuel and at least one of the second fuel and the coolant into the combustion chamber; a base portion configured to receive a first fuel and at least one of a second fuel and a coolant into the body; and a nozzle portion coupled to the base portion, wherein the nozzle portion is configured to be positioned proximate to a combustion chamber for injecting the first fuel and at least one of the second fuel and the coolant into the combustion chamber; a valve seal positioned at or proximate to the nozzle portion; an ignition rod extending from the base portion to the nozzle portion; a valve coaxially disposed over at least a portion of the ignition rod, wherein the valve includes a sealing head and moves between an open position in which the sealing head is spaced apart from the valve seal, and a closed position in which the sealing head at least partially contacts the valve seal; a first flow channel extending longitudinally through a center portion of the ignition rod, wherein the first flow channel is configured to deliver the first fuel to the nozzle portion; a second flow channel fluidly separated from the first flow channel and extending longitudinally through the body adjacent to the valve, wherein the second flow channel is configured to deliver at least one of the second fuel and the coolant to the nozzle portion; a first coupling fluidly coupled to the first flow channel to deliver the first fuel to the first flow channel; and a second coupling fluidly coupled to the second flow channel to deliver at least one of the second fuel and the coolant to the second flow channel.