Electronically controlled engine fuel injection system - uses condenser charge and discharge operation to time cold-start functions

摘要

The system is particularly for an automotive engine where fuel is injected into the intake, having an electronic control unit regulating the opening period of a solenoid injector and containing a multivibrator, preferably monostable. The duration of the output impulse from the latter varies with one or more engine operating parameters, particularly the vacuum downstream of the throttle butterfly. An impulse extension stage is connected to the multivibrator, delivering an extension impulse joined onto the multivibrator output impulse, its duration depending on that of the latter. A cold-start valve with time switch is included, together with means for enrichment of the fuel/air mixture dependent on time and temperature during warming up.