Abstract: A fuel control apparatus and a method for setting a target fuel pressure are disclosed. A fuel delivery conduit accumulates fuel provided from a fuel pump. In turn, a fuel injector injects the fuel accumulated in the fuel delivery conduit while a fuel pressure regulator regulates fuel pressure in the fuel delivery conduit. There is a controller associated with the determination and control of the fuel pressure in the fuel delivery conduit based on at least one operating condition. The controller further selectively lowers the fuel pressure when the engine is in a fuel shortfall condition, where a fuel quantity capable of being injected under the fuel pressure falls short with respect to a desired fuel quantity of the engine.

Abstract: Fuel to be supplied to fuel injectors (31A-31D) of an internal combustion engine is pressurized using a plunger pump (14) which operates in accordance with the rotation of the internal combustion engine. Each of the injectors (31A-31D) injects the supplied fuel into each of a plurality of cylinders at a predetermined crank angle. At a predetermined calculation timing which is prior to a fuel injection timing of each fuel injector (31A-31D), an engine controller (41) predicts a fuel pressure (Pest) at the fuel injection timing with a high degree of precision (S15). When the predicted fuel pressure (Pest) reaches a predetermined injection permission pressure, the fuel injector (31A-31D) is controlled to execute fuel injection (S17, S23), and thus delays in a fuel injection start timing during cranking are prevented.

Abstract: A combustion control system controls combustion in a direct fuel injection spark ignition engine that maintains a constant pressure in an accumulator when fuel is not being injected. The combustion control system controls combustion when fuel injection is resumed after being temporarily stopped. The combustion control system has a target fuel pressure acquiring section that acquires a target fuel pressure based on an engine rotational speed and an engine load, an actual fuel pressure detecting section that the actual fuel pressure, a timing acquiring section, and a first timing control section. The timing acquiring section acquires the fuel injection timing and ignition timing (50 and 30 degrees BTDC) based on the rotational speed and load. The first timing control section controls the fuel injection timing and the ignition timing based on actual fuel pressure, e.g., retards the fuel injection and ignition timings to 40 and 25 degrees BTDC.

Abstract: A combustion control system controls combustion in a direct fuel injection spark ignition engine that maintains a constant pressure in an accumulator when fuel is not being injected. The combustion control system controls combustion when fuel injection is resumed after being temporarily stopped. The combustion control system has a target fuel pressure acquiring section that acquires a target fuel pressure based on an engine rotational speed and an engine load, an actual fuel pressure detecting section that the actual fuel pressure, a timing acquiring section, and a first timing control section. The timing acquiring section acquires the fuel injection timing and ignition timing (50 and 30 degrees BTDC) based on the rotational speed and load. The first timing control section controls the fuel injection timing and the ignition timing based on actual fuel pressure, e.g., retards the fuel injection and ignition timings to 40 and 25 degrees BTDC.