Low-cost fuel injection systems for internal combustion engines, including vapor fuel engines are provided.

A fuel injection control apparatus for an internal combustion engine includes a low pressure fuel pump, a low pressure fuel passage, a high pressure fuel pump, a high pressure fuel passage, a fuel injection valve, a high pressure controller, and a low pressure controller. The low pressure controller calculates a feedforward correction amount that increases as a request injection amount of the fuel injection valve increases and an increase rate of the high pressure target value increases when a high pressure target value increases. The low pressure controller calculates a feedback correction amount based on a low-side pressure deviation when the high pressure target value increases. The low pressure controller controls driving of the low pressure fuel pump based on a sum of the feedforward correction amount and the feedback correction amount.

The present invention describes a fuel-management system for minimizing particulate emissions in turbocharged direct injection gasoline engines. The system optimizes the use of port fuel injection (PFI) in combination with direct injection (DI), particularly in cold start and other transient conditions. In the present invention, the use of these control systems together with other control systems for increasing the effectiveness of port fuel injector use and for reducing particulate emissions from turbocharged direct injection engines is described. Particular attention is given to reducing particulate emissions that occur during cold start and transient conditions since a substantial fraction of the particulate emissions during a drive cycle occur at these times. Further optimization of the fuel management system for these conditions is important for reducing drive cycle emissions.

A method of operating an engine includes operating the engine in first and second engine operating map regions by performing passive jet ignition combustion with a first stoichiometric fuel mixture and a first volume of residual gas. The engine is operated in a third engine operating map region by performing turbulent jet controlled compression ignition (TJCCI) with an ultra lean fuel mixture and a first volume of cooled exhaust gas recirculation, a fourth engine operating map region by performing passive jet ignition combustion with a third stoichiometric fuel mixture and a second volume of cooled exhaust gas recirculation, and a fifth engine operating map region, characterized by shutting off the engine. The engine is operated in a mode transition region between the second, third, and fourth engine operating map regions by performing passive jet ignition combustion with a second stoichiometric fuel mixture and a second volume of residual gas.

Provided is a control device for an internal combustion engine, the control device enabling the suppression of variations in the amount of fuel injected by injection while the boost voltage is charging, without offsetting the injection timing. A boost circuit (211) boosts a first voltage supplied from a battery (201), and supplies a boosted second voltage to a fuel injection device (214). Switches (212, 213) switch the second voltage supplied to the fuel injection device from the booster circuit on and off. Computation devices (204, 207) control the switches. Each computation device comprises: an estimation unit that, before the initial fuel injection in a combustion cycle, estimates the second voltage for all of the fuel injection times in the combustion cycle; and a correction unit that corrects the amount of fuel injected for each fuel injection time depending on the estimated second voltage.

In a hybrid fuel supply system for the same high pressure supply pump used for gasoline direct injection (DI) is also used to supply the port injection (PI) system. For a given pumping stroke, fuel can be delivered only to the DI system, only to the PI system, or a first portion can be delivered to the DI system and a second portion delivered to the PI system. The pumping chamber always fills to maximum volume. Fuel metering for DI is by a control valve, which when closed delivers fuel into the DI system and when opened spills pumped fuel into the PI system. Any spill at high pressure opens a pressure regulating valve in the PI system that dumps fuel at excess pressure to a low pressure region to maintain the PI system at a constant target pressure.

A method for operating a fluid delivery system of a vehicle powerplant is provided. The method includes sampling a fluid pressure in a port injection section of the fluid delivery system, determining if an isolation valve positioned upstream of a direct injection pump is degraded based on the fluid pressure, where the isolation valve separates the port injection section from a direct injection section, and when it is determined that the isolation valve is degraded, indicating said degradation of the isolation valve.

A method for controlling a two-stroke internal combustion engine is disclosed. The engine has at least one combustion chamber, at least one direct fuel injector for injecting fuel directly in the at least one combustion chamber, at least one port fuel injector for injecting fuel upstream of the at least one combustion chamber, and at least one exhaust valve. The method has the steps of supplying a first fuel quantity to the at least one combustion chamber, a first ratio of the first fuel quantity being supplied by the at least one port fuel injector; and supplying a second fuel quantity to the at least one combustion chamber when a position of the at least one exhaust valve changes, a second ratio of the second fuel quantity being supplied by the at least one port fuel injector, the second ratio being different from the first ratio.

An engine control device is provided which includes a first fuel injection valve; a second injection valve provided at such a position that the amount of fuel injected by the second fuel injection valve and adhering to the inner peripheral wall of a cylinder is smaller; a cooling water temperature detector for detecting the temperature of cooling water for cooling an engine; and an injection ratio determining arrangement for determining the ratio between the amount of fuel injected by the first fuel injection valve and the amount of fuel injected by the second fuel injection valve based on the temperature of cooling water. The injection ratio determining arrangement stores an injection amount adjustment operation range in which the injection ratio determining arrangement is configured to increase the fuel injection ratio of the amount of fuel injected by the second fuel injection valve, when the temperature of cooling water falls.

A controller of an engine performs a failure diagnosis process for an injection valve. The failure diagnosis process increases a misfire count of the engine when a variation in rotation of the engine is equal to or greater than a predetermined variation in every predetermined cycle, and determines that the injection valve has a failure when the misfire count is equal to or greater than a first predetermined number of times over a predetermined time period. The controller determines that the multi-cylinder engine is in a predetermined load operation cycle if a volume efficiency of the multi-cylinder engine is less than a reference value, and the controller determines whether continuation of the injection mode is needed based on a comparison of the misfire count and a second predetermined number of times, wherein the second predetermined number of times is less than the first predetermined number of times.