Dual fuel system for an internal combustion engine

A dual fuel system for an engine, comprising:

• at least one supply tank for supplying a first fuel and a second fuel;
• a fuel rail capable of delivering the first fuel and the second fuel to fuel injectors;
• an auxiliary holding tank for storing the second fuel;
• and
• at least one controller configured to (i) evacuate the second fuel from the fuel rail into the holding tank based at least upon the engine being disabled, and (ii) return the second fuel from the auxiliary holding tank to an intake of the engine based upon the engine being restarted;
• wherein the at least one controller is further configured to input the first fuel into the fuel rail subsequent to the evacuation of the second fuel from the fuel rail.

A method of providing a first fuel and a second fuel from at least one tank for operation of a vehicle having an engine and a fuel rail, the method comprising:

• receiving an engine-OFF signal;
• evacuating the second fuel from the fuel rail into a holding container based at least upon the engine-OFF signal;
• supplying the first fuel from the tank to the fuel rail subsequent to the evacuating;
• receiving an engine-ON signal;
• supplying the first fuel from the fuel rail to the engine at a first rate based at least upon the engine-ON signal;
• determining a temperature of the fuel rail;
• and
• supplying the second fuel into the fuel rail based upon the temperature of the fuel rail exceeding a threshold.