System for detecting misfires in an internal combustion engine

US5263365A · kind A · utility

Assignees

• Robert Bosch GmbH · DE
• AUDI AG · DE

Inventors

• Werner Muller · East Greenwich, US
• Wolfgang Wimmer · Rietheim, CH
• Anton Kantschar · Lambach, DE
• Martin Klenk · Munich, DE

Key dates

• Filing date: Jun 5, 1992
• Grant date: Nov 23, 1993
• Expiry date: Jun 5, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G01M15/11
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A system for detecting multiple misfires and for allocating misfires to cylinders for detected multiple misfires in a multi-cylinder internal combustion engine is so configured that the rough-running values for the individual cylinders are determined. The system then however forms sum terms with these rough-running values and, in turn, forms sums with these sum terms which sums are compared with threshold values. When at least one sum exceeds the corresponding threshold value, then this shows the presence of multiple misfires. As soon as multiple misfires are detected, the rough-running threshold values for allocating misfires to cylinders are reduced. Advantageously, the rough-running values are so modified in advance that their correction terms are influenced as little as possible by misfires. In this way, misfires can also reliably be allocated to individual cylinders when multiple misfires are present.