Methods and apparatus for operation of multiple fuel engines

A method for controlling delivery of fuel to a multiple fuel engine utilizing a first fuel and a second fuel, the method comprising:

• a. providing an electronic control unit;
• b. inputting operating characteristics of an electronically controlled engine system to the electronic control unit, wherein at least one of the operating characteristics comprises gas pressure of the second fuel, gas temperature of the second fuel, boost pressure of an intake manifold, or engine coolant temperature;
• c. communicating with the engine system by a data link;
• and
• d. controlling amounts of the first fuel and the second fuel for delivery to the engine based on at least one of the operating characteristics, wherein an operating speed of the engine is maintained below a predetermined governed speed of the engine corresponding to a governed speed of the engine when the engine is only utilizing the first fuel.

A method for calibrating an electronic control unit for a multiple fuel engine utilizing a first fuel and a second fuel, the method comprising:

• a. inputting operating characteristics of an electronically controlled engine system to the electronic control unit;
• b. determining governing characteristics for multiple fuel operation based on the operating characteristics;
• c. communicating with the engine system by a data link;
• and
• d. controlling amounts of the first fuel and the second fuel for delivery to the engine based on the governing characteristics, wherein an operating speed of the engine is maintained below a predetermined governed speed of the engine corresponding to a governed speed of the engine when the engine is only utilizing the first fuel.

A method for converting an electronically controlled engine system of a vehicle to a multiple fuel engine utilizing a first fuel and a second fuel, the method comprising installing an electronic control unit on the vehicle, wherein the electronic control unit comprises:

• a. means for inputting operating characteristics of the engine system to the electronic control unit, wherein at least one of the operating characteristic comprises gas pressure of the first fuel, gas temperature of the second fuel, boost pressure of an intake manifold, or engine coolant temperature;
• b. means for communicating with the engine system by a data link;
• and
• c. means for controlling amounts of the first fuel and the second fuel for delivery to the multiple fuel engine based on at least one of the operating characteristics and maintaining an operating speed of the engine below a predetermined governed speed of the engine corresponding to a governed speed of the engine when the engine is only utilizing the first fuel.

A multiple fuel electronically controlled engine system utilizing a first fuel and a second fuel, the multiple fuel engine system comprising an engine, a storage tank for the first fuel, a first fuel line in flow communication between the storage tank for the first fuel and the engine, a storage tank for the second fuel, a second fuel line in flow communication between the storage tank for the second fuel and the engine, and an electronic control unit comprising:

• a. means for inputting operating characteristics to the electronic control unit, wherein at least one of the operating characteristics comprises gas pressure of the second fuel, gas temperature of the second fuel, boost pressure of an intake manifold, or engine coolant temperature;
• b. means for communicating with the engine system by a data link;
• and
• c. means for controlling amounts of the first fuel and the second fuel for delivery to the multiple fuel engine based on at least one of the operating characteristics and maintaining an operating speed of the engine below a predetermined governed speed of the engine corresponding to a governed speed of the engine when the engine is only utilizing the first fuel.

A computer readable medium containing instructions which, when executed by a processor, performs a method for operating a multiple fuel engine utilizing a first fuel and a second fuel, the method comprising:

• a. inputting operating characteristics of an engine system to an electronic control unit;
• b. determining governing characteristics for multiple fuel operation based on the operating characteristics;
• and
• c. controlling amounts of the first fuel and the second fuel for delivery to the engine based on the governing characteristics, wherein an operating speed of the engine is maintained below a predetermined governed speed of the engine corresponding to a governed speed of the engine when the engine is only utilizing the first fuel.