Fuel controller for internal combustion engine

• US 4,962,740 A
• Filed: 08/28/1989
• Issued: 10/16/1990
• Est. Priority Date: 08/29/1988
• Status: Expired due to Term

• Current Assignee: GEC Marconi Limited (Gooding Consumer Electronics Ltd.)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Fujimoto, Takanori, Hara, Toshiro
• Primary Examiner(s): Wolfe, Willis R.
• Application Number:
  US07/399,144
• Time in Patent Office: 414 Days
• Field of Search: 123/436, 123/479, 123/481, 123/198 DB, 364/431.05, 364/431.08, 364/431.09, 73/117.3
• US Class Current: 123/481
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: G01M 15/11 by detecting misfire

Abstract

A fuel controller for an internal combustion engine senses misfiring in an engine cylinder by sensing changes in the rotational speed of the engine between prescribed crankshaft angles due to a reduction in torque when misfiring occurs. When misfiring occurs, the supply of fuel to the misfiring cylinder is cut off for a prescribed number of engine rotations and then the supply of fuel is restarted. A warning indicator is turned on as long as misfiring is detected by the misfiring sensor.

Claims

1. A fuel controller for an internal combustion engine having a plurality of cylinders and a plurality of fuel injectors which individually supply fuel to the cylinders, comprising:

misfiring sensing means for sensing a misfiring in any one of the cylinders of the engine; and

fuel supply cut-off means for cutting off the supply of fuel to the misfiring cylinder for a prescribed number of rotations of the engine.

2. A fuel controller as claimed in claimed in claim 1, wherein said misfiring sensing means comprises:

means for measuring the engine rotational speed during the power stroke of each cylinder; and

means for determining when there is a change in the rotational speed between successive power strokes of greater than a prescribed quantity.

3. A fuel controller as claimed in claim 1, further comprising a warning indicator responsive to said misfiring sensing means for providing a warning as long as misfiring is detected by said misfiring sensing means.

4. A method for controlling the fuel supply to an internal combustion engine having a plurality of cylinders and a plurality of fuel injectors which supply fuel to the cylinders, comprising:

measuring the rotational speed of the engine during each power stroke of the engine;

detecting a misfiring cylinder of the engine by comparing the engine rotational speed for successive power strokes of the engine;

cutting off the supply of fuel to the misfiring cylinder; and

restarting the supply of fuel to the misfiring cylinder after a prescribed number of rotations of the engine.

5. A method as claimed in claim 4, wherein the step of detecting a misfiring cylinder comprises determining when the engine rotational speed during the power stroke of a cylinder is less than the engine rotational speed during the power stroke of the preceding cylinder by more than a prescribed quantity.

6. A method as claimed in claim 4, wherein the step of detecting a misfiring cylinder comprises determining when the rotational speed for the power stroke of a cylinder is less than the rotational speed during the power stroke of the preceding cylinder by more than a prescribed percent.

7. A method as claimed in claim 4, further comprising the step of providing a warning indication as long as misfiring is detected.