US 7,111,454 B2 · Fuel control compensation for secondary air system flow variation

Abstract

An engine control system and method maintains an optimum exhaust fuel to air ratio in an internal combustion engine. A secondary air injection (SAI) pressure is measured in an SAI system. The SAI pressure measurement is converted into an SAI flow value. A fuel compensation value is obtained based on the SAI flow value. Fuel delivery is compensated to the engine based on the fuel compensation value. In a second embodiment, the fuel compensation value is obtained based on the SAI pressure measurement. Fuel delivery is compensated to the engine based on the fuel compensation value. In a third embodiment, a primary flow value is calculated at an air intake of the engine. A fuel compensation value is calculated based on the SAI flow and primary flow values. Fuel delivery to the engine is compensated based on the fuel compensation value.

Claims8

Dependent claims

A control system for maintaining an optimum exhaust fuel to air ratio in an internal combustion engine, comprising:

an engine having an primary air intake and a fuel injection system;
an exhaust system connected to said engine and having a catalytic converter;
a secondary air injection (SAI) system connected to the exhaust system;
an SAI pressure sensor disposed in said SAI system that generates an SAI pressure measurement;
a controller that communicates with said SAI pressure sensor, said primary intake and said fuel injection system and that compensates fuel delivery into said engine based directly on said SAI pressure measurement from said SAI pressure sensor;
and
wherein said controller includes a compensator that receives said SAI pressure measurement and outputs a desired fuel compensation value.

4 more elements

Dependencies are inferred from the claim text.

Fuel control compensation for secondary air system flow variation

Life of this patent

Fuel control compensation for secondary air system flow variation

Life of this patent

Abstract

Claims8