Abstract: In at least some implementations, a method of controlling fuel injection events, includes determining at least one engine operating condition, determining timing of a desired pressure in an engine intake chamber or at the outlet of a fuel injector, and initiating a fuel injection event as a function of the at least one engine operating condition and the desired pressure. The fuel injection event is initiated prior to the desired pressure occurring and wherein the fuel injection event occurs for a duration such that the fuel injection event terminates after the desired pressure occurs.

Abstract: In at least some implementations, a method of controlling fuel injection events, includes determining at least one engine operating condition, determining timing of a desired pressure in an engine intake chamber or at the outlet of a fuel injector, and initiating a fuel injection event as a function of the at least one engine operating condition and the desired pressure. The fuel injection event is initiated prior to the desired pressure occurring and wherein the fuel injection event occurs for a duration such that the fuel injection event terminates after the desired pressure occurs.

Abstract: In at least some implementations, a method of control-ling fuel injection events, includes determining at least one engine op-erating condition, determining timing of a desired pressure in an engine intake chamber or at the outlet of a fuel injector, and initiating a fuel injection event as a function of the at least one engine operating condition and the desired pressure. The fuel injection event is initiated prior to the desired pressure occurring and wherein the fuel injection event occurs for a duration such that the fuel injection event terminates after the desired pressure occurs.

Abstract: In at least some implementations, a method of forming a diaphragm for a liquid pump, includes clamping a substantially planar piece of material about a periphery, and plastically deforming the piece of material inboard of the clamped periphery. In at least some implementations, the material is plastically deformed by pressing a forming member against the material, or the material is plastically deformed by applying a fluid under pressure against the material.

Abstract: A method and apparatus controlling the fuel-to-air ratio of a fuel and air mixture supplied to an operating engine includes the steps of determining a first engine speed before enleanment of the mixture, determining a second engine speed near or at the end of a period of enleanment of the mixture, and after ending the enleanment, determining whether the engine speed recovers within a predetermined range of the first engine speed and if so determining a delta speed difference between the first and second speeds and using this delta speed difference as a factor in determining a change in the fuel-to-air ratio of the fuel mixture supplied to the engine.

Abstract: In at least some implementations, a diaphragm for a fluid pump includes a first layer formed from a first material that inhibits or prevents vapor permeation through the diaphragm, and a second layer coupled to the first layer and formed from a second material different than the first material. The first material may include at least one of fluoropolymers, perfluoroalkoxy (PFA), polyfluoroethylenepropylene (FEP), polytetrafluoroethylene (PTFE), liquid crystal polymers, nylons, thin metal foil or film, or ethylene vinyl alcohol, and the fluoropolymer may be a fluoroelastomer. The first layer may be continuous and without perforations in an area of the diaphragm adapted to be exposed to a fluid. The first layer may include a base material and a coating that prevents vapor permeation therethrough. The second material may include at least one of NBR rubber, H-NBR, NBR coated or impregnated fiber or nylon materials, or a fluoroelastomer.

Abstract: A method and apparatus controlling the fuel-to-air ratio of a fuel and air mixture supplied to an operating engine includes the steps of determining a first engine speed before enleanment of the mixture, determining a second engine speed near or at the end of a period of enleanment of the mixture, and after ending the enleanment, determining whether the engine speed recovers within a predetermined range of the first engine speed and if so determining a delta speed difference between the first and second speeds and using this delta speed difference as a factor in determining a change in the fuel-to-air ratio of the fuel mixture supplied to the engine.

Abstract: In at least some implementations, a method of controlling engine idle speed includes comparing engine speed to a speed threshold where the speed threshold may include a range of speeds, if the engine speed is outside of the speed threshold, adjusting the timing of an ignition spark up to a threshold amount of ignition timing adjustment, and if the engine speed is not within said speed threshold after adjustment up to the threshold amount of ignition timing adjustment then adjusting the air/fuel mixture provided to the engine to bring the engine speed within said speed threshold.

Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

Abstract: In at least some implementations, an engine control process includes an engine speed test and other steps. The engine speed test includes the steps of a) determining a first engine speed, b) changing the air/fuel ratio of a fuel mixture delivered to the engine, and c) determining a second engine speed after at least some of the air/fuel ratio changing event, Based at least in part on the difference between the first engine speed and the second engine speed it is determined if a change in the air/fuel ratio of the fuel mixture delivered to the engine is needed. If a change to the air/fuel ratio was indicated, the air/fuel ratio of a fuel mixture delivered to the engine is changed.

Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

Abstract: In at least some implementations, an engine control process includes an engine speed test and other steps. The engine speed test includes the steps of a) determining a first engine speed, b) changing the air/fuel ratio of a fuel mixture delivered to the engine, and c) determining a second engine speed after at least some of the air/fuel ratio changing event, Based at least in part on the difference between the first engine speed and the second engine speed it is determined if a change in the air/fuel ratio of the fuel mixture delivered to the engine is needed.

Abstract: A method of operating an engine is disclosed, which includes determining a peak power condition for the engine, measuring a temperature associated with the engine at said peak power condition, comparing the temperature measured with a previously determined temperature associated with a known peak power condition of the engine, determining an offset value based on the comparison made in step, controlling at least one of an air-fuel mixture delivered to the engine or ignition spark timing based on said offset value. Various engine fuel delivery systems, carburetors, fuel injection and control systems also are disclosed.

Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

Abstract: A method, fuel system, and components for facilitating the delivery of liquid fuel from a fuel tank in fluid communication with a float bowl carburetor of an internal combustion engine, wherein evaporative emissions of the fuel from the fuel tank and float bowl carburetor are mitigated. During operation of the engine, fluid communication is permitted between the fuel tank and the carburetor, and fuel vapors at a predetermined threshold superatmospheric pressure are permitted to vent outwardly from the fuel tank. During inoperation of the engine, fluid communication is prevented between the fuel tank and the carburetor, and fuel vapors at a predetermined threshold superatmospheric pressure are permitted to vent outwardly from the fuel tank.

Abstract: A method of operating an engine is disclosed, which includes determining a peak power condition for the engine, measuring a temperature associated with the engine at said peak power condition, comparing the temperature measured with a previously determined temperature associated with a known peak power condition of the engine, determining an offset value based on the comparison made in step, controlling at least one of an air-fuel mixture delivered to the engine or ignition spark timing based on said offset value. Various engine fuel delivery systems, carburetors, fuel injection and control systems also are disclosed.

Abstract: A priming and purging fuel system for an internal combustion engine purges a diaphragm carburetor of the engine of stale liquid fuel and accumulated fuel vapor and air while simultaneously priming the carburetor and/or engine with liquid fuel for starting. A start pump of the fuel system supplies at least liquid fuel to a priming circuit and preferably at least fuel vapor and air to a purging circuit of the fuel system. The priming circuit delivers the priming fuel to the engine via a conduit that leads to an isolation chamber located between an inlet jet and preferably an outlet jet. The cross sectional flow area of the jets are appropriately sized to flow a needed amount of priming fuel to the carburetor and/or engine for starting without flooding the engine. The combination of the enlarged isolation chamber and jets, at least substantially prevents fuel dribble from the priming circuit and into the engine while running.

Abstract: A method, fuel system, and components for facilitating the delivery of liquid fuel from a fuel tank in fluid communication with a float bowl carburetor of an internal combustion engine, wherein evaporative emissions of the fuel from the fuel tank and float bowl carburetor are mitigated. During operation of the engine, fluid communication is permitted between the fuel tank and the carburetor, and fuel vapors at a predetermined threshold superatmospheric pressure are permitted to vent outwardly from the fuel tank. During inoperation of the engine, fluid communication is prevented between the fuel tank and the carburetor, and fuel vapors at a predetermined threshold superatmospheric pressure are permitted to vent outwardly from the fuel tank.

Abstract: A priming and purging fuel system for an internal combustion engine purges a diaphragm carburetor of the engine of stale liquid fuel and accumulated fuel vapor and air while simultaneously priming the carburetor and/or engine with liquid fuel for starting. A start pump of the fuel system supplies at least liquid fuel to a priming circuit and preferably at least fuel vapor and air to a purging circuit of the fuel system. The priming circuit delivers the priming fuel to the engine via a conduit that leads to an isolation chamber located between an inlet jet and preferably an outlet jet. The cross sectional flow area of the jets are appropriately sized to flow a needed amount of priming fuel to the carburetor and/or engine for starting without flooding the engine. The combination of the enlarged isolation chamber and jets, at least substantially prevents fuel dribble from the priming circuit and into the engine while running.