Abstract: A pressurized fuel tank maintains fuel in its liquid phase and is connected to a fuel pump providing fuel to an accumulator. Control valves control fuel flow to injectors feeding fuel to combustion cylinders. When the engine is shut down, one way check valves connected between the control valves and the injectors close to seal the injectors from the control valves; and at the same time, a dump valve opens to connect the injectors to an adsorber device while an air inlet valve also opens to connect the adsorber device to the engine air inlet. When the engine is restarted, the check valves open and the dump valve and air inlet valve close. Subsequently, a purge valve opens to connect the adsorber device to a source of purge air, while the air inlet valve opens simultaneously. A purge process then occurs, whereupon the purge valve and air inlet valve simultaneously close, and the engine operates with the dump valve, the air inlet valve and the purge valve in closed position until the engine shuts down again.

Abstract: An internal combustion engine that is driven by fuels such as dimethyl ether (DME) that have a viscosity less than 1.0 and a storage and delivery system for the fuel that will reduce considerably the emissions of NO.sub.x and particulate. The fuel delivery system includes a fuel injector nozzle valve being forced closed by fuel that has leaked past a solenoid operated valve and is at a pressure less than the valve opening pressure.

Abstract: An internal combustion engine that is driven by fuels such as dimethyl ether (DME) that have a viscosity less than 1.0 and a storage and delivery system for the fuel that will reduce considerably the emissions of NO.sub.x and particulate. The fuel delivery system includes a fuel injector nozzle valve being forced closed by fuel, that has leaked past a solenoid operated valve and is at a pressure less than the valve opening pressure.

Abstract: Fuel injection system for an internal combustion engine with direct fuel injection, with an electromagnetic control valve for pressurization of a medium-pressure space, and a hydraulic amplification plunger comprising a medium-pressure plunger adjacent to the medium-pressure space and a high-pressure plunger adjacent to a high-pressure space, which latter is connected to a fuel delivery line on the one side and a nozzle space surrounding the fuel needle on the other side, the high-pressure space connecting to a fuel bypass line in at least one intermediate position of the high-pressure plunger. To improve rate shaping, especially at the beginning and end of injection, the proposal is put forward that in addition to the high-pressure plunger a pressure-dependent bypass valve be located in the flow path between the high-pressure space and the fuel bypass line, which bypass valve opens the flow connection between high-pressure space and fuel bypass line for a narrow range of pressures in the high-pressure space.

Abstract: An internal combustion engine that is driven by dimethyl ether (DME) and a storage and delivery system for the DME that will reduce considerably the emissions of NO.sub.x and particulate. Existing internal combustion engines, fueled by conventional fuels can be economically converted to the use of DME as a fuel.

Abstract: An internal combustion engine that is driven by dimethyl ether (DME) and a storage and delivery system for the DME that will reduce considerably the emissions of NO.sub.x and particulate. Existing internal combustion engines, fueled by conventional fuels can be economically converted to the use of DME as a fuel.

Abstract: A diesel engine hydraulically-actuated, electronically-controlled unit injector fuel injection system is provided with a two-stage pump system including two parallel pumps for supplying actuating fluid to the injectors. The first stage pump of this two-stage pump has a capacity which is adequate for most operating modes. The second stage pump is used for starting and for high engine load situations. The second stage pump is controlled by a solenoid bypass valve that switches in the second stage pump when the pressure in the high pressure rails fall below a desired or programmed level. An embodiment of this invention includes a second bypass circuit having a fast-response, solenoid-actuated bypass valve that bypasses all of the flow from both stages between injections and thereby produces a pulsed flow of actuation fluid to produce the required pressure for each engine fuel injection while unloading the pumping system between injections.

Abstract: An exhaust back pressure control system includes a valve in the exhaust outlet of a turbocharger of an internal combustion engine which is controlled by an engine control microcomputer. When the valve is moved toward a closed position, it restricts the exhaust flow, thereby increasing back pressure and friction within the engine by producing an artificial load thereon, and thus speeds up the warming process taking place within the engine upon starting thereof. The valve is moved by an actuating piston within a hydraulic cylinder using engine oil pressure controlled by an electrically operated valve receiving a pulse width modulated operating signal from the engine microcomputer, the operating signal being generated to provide a desired back pressure as a function of engine coolant temperature, engine speed, engine fuel comsumption, and actual back pressure. Operation of the system is enabled if the ambient air temperature is below 2.degree. C.

Abstract: In combination with a diesel engine, an engine air intake conduit leading preferably to a turbocharger, a source of fuel, and a circuitous fuel path supplying fuel to the engine from the source and returning uncombusted fuel from the engine to the source, is a fuel cooler. The fuel cooler is mounted within the engine air intake conduit upstream of the turbocharger, if present, in a manner allowing intake air to flow through a central passageway of the cooler to the turbocharger. The fuel cooler is further engaged within the circuitous fuel path in a manner allowing heated fuel to travel through a peripheral passageway formed in the fuel cooler. The peripheral passageway is contiguous to the central passageway whereby heat from the heated fuel is transferred to the intake air, thus cooling the fuel. The fuel cooler is used preferably in cooling uncombusted diesel fuel being returned toward the storage tanks of a vehicle from the engine.

Abstract: A dynamic engine power test method comprises operating the engine at a low speed, accelerating the engine at full throttle to a predetermined high speed, such as high idle, without absorbing or dissipating power therefrom, measuring the engine speed and elapsed time to determine the angular acceleration at specific speeds in the operating range of the engine or during one or more relatively small discrete speed intervals or windows preferably corresponding to peak torque speed, an intermediate point, rated speed, and a speed between rated speed and high idle. The torque output of the engine may be calculated manually or preferably automatically for each speed interval based on the equation T=I.alpha. wherein .alpha. is the angular acceleration at that speed and the horsepower for a nominal speed in the interval may also be calculated based on the torque.

Abstract: An automotive diesel engine is provided with pistons which carry two compression rings and an oil control ring in the conventional manner, the cold end clearance of the second compression ring being greatly exaggerated compared to the cold end clearance of the top compression ring and the annulus defined by the second land of the piston, the two compression rings and the engine cylinder wall having an empirically determined volume, preferably in the range of about 0.12 cubic inches to about 0.35 cubic inches. The top land of the piston is preferably set back to provide exaggerated diametrical clearance with the cylinder wall.