Diagnosing system for engine

• US 6,330,510 B1
• Filed: 08/12/1999
• Issued: 12/11/2001
• Est. Priority Date: 08/12/1998
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Takaku, Yutaka, Nogi, Toshiharu, Ishii, Toshio
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US09/372,984
• Time in Patent Office: 852 Days
• Field of Search: 123/295, 123/305, 123/435, 123/436, 701/102, 701/103, 701/104, 701/105, 701/111, 701/114, 701/115, 731/16, 731/173
• US Class Current: 701/114
• CPC Class Codes: F02D 2041/389 for injecting directly into the cylinder
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements

Abstract

A diagnosing system for an engine diagnoses malfunctions that occur in a direct-injection engine in which fuel is injected into combustion chambers or a lean-burn engine. The present invention provides a diagnosing system for an engine capable of diagnosing malfunctions in an intake air flow intensifying component and a fuel supply component and of specifying a malfunctioning part without being affected by the difference between different engines, the difference in quality between parts and aging. The diagnosing system for an engine comprises: a selecting component for selecting either a first air-fuel mixture control component or a second air-fuel mixture control component according to operating condition of an engine; a combustion condition detecting component for detecting combustion condition of the engine; and decision component for deciding a malfunction on the basis of a first combustion condition detected by the combustion condition detecting component in a state where the first air-fuel mixture control component is selected by the selecting component, and a second combustion condition detected by the combustion condition detecting component in a state where the second air-fuel mixture control component is selected by the selecting component.

Claims

1. A diagnosing system for an engine comprising a selecting component for selecting either a first air-fuel mixture control component or a second air-fuel mixture control component according to operating condition of an engine;

a combustion condition detecting component for detecting combustion condition of the engine; and

decision component for deciding a malfunction on the basis of a first combustion condition detected by the combustion condition detecting component in a state where the first air-fuel mixture control component is selected by the selecting component, and a second combustion condition detected by the combustion condition detecting component in a state where the second air-fuel mixture control component is selected by the selecting component, wherein the decision component decides that an air flow intensifying component for intensifying the flow of intake air is malfunctioning when the difference between the first combustion condition and the second combustion condition is not smaller than a predetermined value.

2. A diagnosing system for an engine comprising a selecting component for selecting either a first air-fuel mixture control component or a second air-fuel mixture control component according to operating condition of an engine;

a combustion condition detecting component for detecting combustion condition of the engine; and

decision component for deciding a malfunction on the basis of a first combustion condition detected by the combustion condition detecting component in a state where the first air-fuel mixture control component is selected by the selecting component, and a second combustion condition detected by the combustion condition detecting component in a state where the second air-fuel mixture control component is selected by the selecting component, wherein the decision component decides, when the difference between the first combustion condition and the second combustion condition in a specific cylinder is not smaller than a predetermined value, that a fuel supply component for the same cylinder is malfunctioning.

3. A diagnosing system for an engine comprising a selecting component for selecting either a first air-fuel mixture control component or a second air-fuel mixture control component according to operating condition of an engine;

a combustion condition detecting component for detecting combustion condition of the engine; and

decision component for deciding a malfunction on the basis of a first combustion condition detected by the combustion condition detecting component in a state where the first air-fuel mixture control component is selected by the selecting component, and a second combustion condition detected by the combustion condition detecting component in a state where the second air-fuel mixture control component is selected by the selecting component, further comprising an air-fuel mixture control component selection inhibiting component which inhibits selecting operation of the selecting component to hold an operating condition using either the first or the second air-fuel mixture control component when the decision component decides that a malfunction has occurred.

4. A diagnosing system for an engine comprising a selecting component for selecting either a first air-fuel mixture control component or a second air-fuel mixture control component according to operating condition of an engine;

a combustion condition detecting component for detecting combustion condition of the engine; and

decision component for deciding a malfunction on the basis of a first combustion condition detected by the combustion condition detecting component in a state where the first air-fuel mixture control component is selected by the selecting component, and a second combustion condition detected by the combustion condition detecting component in a state where the second air-fuel mixture control component is selected by the selecting component, further comprising a selected operating condition changing component for changing an operating condition where the selecting component executes a selecting operation, when the decision component decides that a malfunction has occurred.