Methods and systems for diagnosing operation of an evaporative emissions system are described. The methods and systems may include increasing an amount of vacuum stored in an evaporative emissions system during discontinuously operating an engine in a boosted operating mode. Storing vacuum allows the evaporative emissions system to reach a desired vacuum level to verify absence of an evaporative emissions system breech.

A throttle body fuel injection system and method that is arranged to easily replace four-barrel carburetors includes a throttle body assembly with four main bores, each with a throttle plate and an associated fuel injector. Each injector feeds fuel into a circular fuel distribution ring via a fuel injection conduit, which introduces pressurized fuel into the air stream. The fuel distribution rings and bores have profiles that avoid constrictions for to prevent low pressure zones according to the Venturi effect. The throttle body includes an idle air control circuit having a port opening into main intake bores downstream of the point of fuel distribution into the air stream, thereby reducing the tendency for a lean fuel mixture at idle. An ECU “feed forward” algorithm controls fuel injection as a function of the position of the idle air control valve.

Various methods and systems are provided for an intake manifold for an engine. In one example, an insert comprises an annular body having a top surface, bottom surface, inner surface, and outer surface. The insert further comprises a first groove for coupling an intake air port of an intake manifold to a cylinder head, a second groove for circulating gaseous fuel received from a gas runner of the intake manifold, and one or more openings to fluidically couple the second groove to an interior of the intake air port. The insert is configured to mix gaseous fuel and intake air at a coupling location between the intake manifold and the cylinder head.

Various methods and systems are provided for an intake manifold for an engine. In one example, an insert comprises an annular body having a top surface, bottom surface, inner surface, and outer surface. The insert further comprises a first groove for coupling an intake air port of an intake manifold to a cylinder head, a second groove for circulating gaseous fuel received from a gas runner of the intake manifold, and one or more openings to fluidically couple the second groove to an interior of the intake air port. The insert is configured to mix gaseous fuel and intake air at a coupling location between the intake manifold and the cylinder head.

A system and method for condensation management in a low-pressure loop EGR system are provided. The system includes an EGR condensation temperature module configured to determine an EGR condensation temperature of recirculated exhaust gas upstream of an EGR cooler and an EGR coolant temperature controller communicably coupled to the EGR condensation temperature module. The EGR coolant temperature controller provides EGR coolant to the EGR cooler at or above the EGR condensation temperature. The system also includes a charge air condensation temperature module configured to determine a charge air condensation temperature of charge air upstream of a charge air cooler and a charge air coolant temperature controller communicably coupled to the charge air condensation temperature module. The charge air coolant temperature controller provides charge air coolant to the charge air cooler at or above the charge air condensation temperature.

In a gas engine provided with a gas supply pipe (35) branching into a supercharger-side gas supply pipe (33) and a cylinder-side gas supply pipe (37), a supercharger-side gas adjusting valve (43) and a cylinder-side gas adjusting valve (45) for controlling flow rates of passages, when the gas concentration of the fuel gas changes, the cylinder-side gas adjusting valve is controlled first to keep the output of the gas engine constant and then the supercharger-side gas adjusting valve is controlled to achieve the fuel gas flow rate Q1 based on the constant flow ratio by means of a gas supply controller (63), while maintaining the flow rate ratio Q1/Q2 at a constant value where Q1 is a fuel gas flow rate in the supercharger-side gas supply pipe and Q2 is a fuel gas flow rate in the cylinder-side gas supply pipe.

In a gas engine provided with a gas supply pipe (35) branching into a supercharger-side gas supply pipe (33) and a cylinder-side gas supply pipe (37), a supercharger-side gas adjusting valve (43) and a cylinder-side gas adjusting valve (45) for controlling flow rates of passages, when the gas concentration of the fuel gas changes, the cylinder-side gas adjusting valve is controlled first to keep the output of the gas engine constant and then the supercharger-side gas adjusting valve is controlled to achieve the fuel gas flow rate Q1 based on the constant flow ratio by means of a gas supply controller (63), while maintaining the flow rate ratio Q1/Q2 at a constant value where Q1 is a fuel gas flow rate in the supercharger-side gas supply pipe and Q2 is a fuel gas flow rate in the cylinder-side gas supply pipe.

The present disclosure relates to a gas engine heat pump including: an engine which burns a mixed air of air and fuel; a first exhaust flow path which is connected to the engine so that exhaust gas discharged from the engine passes through and is discharged to the outside; a turbo charger including: a first compressor which compresses the mixed air and supplies to the engine, and a first turbine which is installed in the first exhaust flow path and receives the exhaust gas passing through the first exhaust flow path to drive the first compressor; a supercharger which is installed in the first exhaust flow path between the engine and the first turbine, and receives and compresses the exhaust gas passing through the first exhaust flow path to supply to the first turbine; a second exhaust flow path which is branched from the first exhaust flow path between the engine and the supercharger, and converges to the first exhaust flow path between the supercharger and the first turbine; a first valve which is installed to be opened and closed in the second exhaust flow path; a third exhaust flow path which is branched from the first exhaust flow path between the supercharger and the first turbine, and converges to the first exhaust flow path in downstream of the first turbine; a second valve which is installed to be opened and closed in the third exhaust flow path; and a controller which controls operations of the first valve, the second valve, and the supercharger according to load of the engine.

The present disclosure relates to a gas engine heat pump including: an engine which burns a mixed air of air and fuel; a first charger which compresses the mixed air and supplies to the engine; a first exhaust flow path which is connected to the engine, and through which exhaust gas discharged from the engine flows; and a second charger which is driven by the exhaust gas branched from the first exhaust flow path to a second exhaust flow path, and compresses the exhaust gas discharged from the engine and supplies the compressed exhaust gas to the engine, thereby reducing the emission of nitrogen oxide by recirculating the exhaust gas without additional power consumption.

The present disclosure relates to a gas engine heat pump including: an engine which burns a mixed air of air and fuel; a first exhaust flow path which is connected to the engine so that exhaust gas discharged from the engine passes through and is discharged to the outside; a turbo charger including: a first compressor which compresses the mixed air and supplies to the engine, and a first turbine which is installed in the first exhaust flow path and receives the exhaust gas passing through the first exhaust flow path to drive the first compressor; a supercharger which is installed in the first exhaust flow path between the engine and the first turbine, and receives and compresses the exhaust gas passing through the first exhaust flow path to supply to the first turbine; a second exhaust flow path which is branched from the first exhaust flow path between the engine and the supercharger, and converges to the first exhaust flow path between the supercharger and the first turbine; a first valve which is installed to be opened and closed in the second exhaust flow path; a third exhaust flow path which is branched from the first exhaust flow path between the supercharger and the first turbine, and converges to the first exhaust flow path in downstream of the first turbine; a second valve which is installed to be opened and closed in the third exhaust flow path; and a controller which controls operations of the first valve, the second valve, and the supercharger according to load of the engine.