Method and system for controlling flexible fuel vehicle fueling

Abstract

An adaptive fuel control system and method directed for use in a motor vehicle powered by a fuel-injected engine and having a fuel tank and a fuel rail and which is operative to run on a plurality of fuels and fuel blends. The system includes a refueling mixer which acts as a fluid damper to slowly introduce new fuel into the fuel rail and correspondingly slow the rate at which new fuel composition is mixed with existing fuel. A stratification mixer is also utilized to re-mix components of blended fuels which may have separated at cold temperatures. An Exhaust Gas Oxygen sensor (EGO) monitors engine exhaust gases and generates a corresponding electrical signal when the air/fuel mixture of the fuel switches between rich and lean. Finally, an electronic control assembly communicates with the EGO and the fuel injectors to generate and store in memory an updatable extended adaptive fuel control table of air/fuel ratio multipliers for selected engine load/engine speed cells. The ECA is adapted to update each of the cells in an amount proportional to the distance the corresponding load point is away from the corresponding load point of all bordering cells. The ECA further generates and stores an updatable counter table and an updatable time stamping table which, together, are operative to adjust the fuel injectors to provide the correct adaption for the current fuel at the current engine speed and engine load.

Dependencies are inferred from the claim text.