Engine with spark ignition operation through the oil pressure switch after fuel shutoff
US4768480A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1987 |
| Grant date | Sep 6, 1988 |
| Priority date | — |
| Expiry date | Dec 10, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/042
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A motor vehicle engine includes an operator controlled fuel injection enabling switch effective to disconnect electric fuel injection apparatus from an electric power source and thus initiate the cessation of engine operation when deactivated. However, the spark ignition system is still powered through an oil pressure switch so as to continue engine operation for a few extra crankshaft rotations to reduce the unburned fuel in the intake passage as the engine stops and thus reduce throttle bore coking. In a vehicle having a fuel pump relay activated by the fuel injection enabling switch with contacts connected across the oil pressure switch, the invention may be obtained by changing the power connection of the spark ignition system from the fuel injection enabling (ignition) switch to the fuel pump relay.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.