Disclosed herein is a diesel ISG vehicle, including an engine ECU controlling a rail pressure of a common rail engine system, in which the engine ECU determines a cold start of the engine based on detected cooling water temperature and detected fuel temperature at the time of engine restarting by idle go of the idle stop & go (ISG) and then restarts the engine by a quick rail pressure control mode in which the pressure of the fuel pumped to a common rail is controlled or restarts the engine by a normal rail pressure control mode in which the flow rate and the pressure of the fuel is controlled, thereby improving the fuel efficiency by the ISG restarting which does not increase a driving torque of a high pressure pump, particularly, reducing a fuel injection quantity by reduction in a loss of accessories such as pump and compressor.

Aspects and embodiments disclosed herein indicate a correlation exists between a specific gravity of combustible fuel and the occurrence of low-speed pre-ignition (LSPI) within engines. Thus techniques are disclosed herein for online measurement of the specific gravity of fuel within an engine, and allow for preventative measures to be executed to minimize or otherwise mitigate the incidence of LSPI when the calculated specific gravity of the fuel exceeds a predefined threshold. In an embodiment, the preventative measures may include, for example, altering or otherwise adjusting an engine map such that an injection timing scheme injects less poor-quality fuel into engine cylinders, thus advantageously preventing the engine from operating at full-power when conditions for LSPI are present.

Systems and methods are provided for a high-pressure fuel pump to mitigate audible ticking noise associated with opening and closing of a digital inlet valve of the high-pressure pump. To reduce the ticking noise associated with the high-pressure pump when the engine is idling, a solution is needed that is simple and does not involve retrofitting the fuel system with noise, vibration, and harshness countermeasures to mask the noise. Pressure devices and associated operation methods are provided that involve adding a combination of several check valves, an accumulator, and a flow control valve with weep channels to allow the digital inlet valve to be deactivated during engine idling as defined by a threshold engine speed.

A fuel pump has a low pressure fuel inlet (40) and a single piston pumping chamber (10) for supplying high pressure fuel through a pump outlet to an inlet side of a common rail (16). The fuel pump comprises a primary pressure relief valve (12) having an inlet side in hydraulic communication with the inlet side of the common rail (16) and an outlet side in fluid communication with the pumping chamber (10); and an auxiliary pressure relief valve (19) having an inlet side (35) in hydraulic communication with the pumping chamber (10) and an outlet side in direct fluid communication with a fuel passage (37) at the low pressure of the pump inlet (40).

The embodiments herein provide a fuel anti-freeze system comprising a temperature sensor, an Engine Control Unit (ECU), a combustion rail pump and two electrical valves. The temperature sensor reports an atmospheric temperature of a fuel rail to the ECU. The ECU controls the combustion rail pump and the electrical valves to control a depletion of the fuel from the fuel rail to a fuel tank, when the atmosphere temperature in the fuel rail is below a threshold temperature. The system empties the fuel rail when the atmosphere temperature is below the threshold temperature, thereby preventing freezing and stiffing of the fuel in the fuel rail of an internal combustion engine. The first electrical valve transfers the fuel from the fuel rail to the fuel tank, and the second electrical valve transfers the fuel from the fuel rail to the fuel tank.

A fuel pump for a direct injection internal combustion engine having a housing defining a pump chamber. Driven and idler toothed gears are rotatably mounted within the pump chamber so that the driven and idler gears are in mesh with each other at a predetermined location in the pump chamber. A fluid inlet is formed through the housing and open to an inlet subchamber in the pump chamber. A fluid outlet is also formed through the housing and open to an outlet subchamber in the pump chamber. A pressure relief passageway fluidly connects the inlet subchamber to the outlet subchamber and a valve is disposed in series with the pressure relief passageway. A control circuit controls the actuation of the valve to control the pump pressure at the pump outlet.

Disclosed herein is a diesel ISG vehicle, including an engine ECU controlling a rail pressure of a common rail engine system, in which the engine ECU determines a cold start of the engine based on detected cooling water temperature and detected fuel temperature at the time of engine restarting by idle go of the idle stop & go (ISG) and then restarts the engine by a quick rail pressure control mode in which the pressure of the fuel pumped to a common rail is controlled or restarts the engine by a normal rail pressure control mode in which the flow rate and the pressure of the fuel is controlled, thereby improving the fuel efficiency by the ISG restarting which does not increase a driving torque of a high pressure pump, particularly, reducing a fuel injection quantity by reduction in a loss of accessories such as pump and compressor.