Fuel vapor recovery system purging method for internal combustion engine by detecting intake manifold pressure and comparing with purge manifold pressure threshold

摘要

The method involves the steps of determining that the vapor recovery system is not operating in a purge mode and that the vapor recovery system should be purged. It involves detecting intake manifold pressure and comparing with predetermined purge manifold pressure threshold and decreasing intake manifold pressure if it exceeds this threshold. At least one valve (58) in the vapor recovery system is actuated to open communication between the vapor recovery system and the air intake (12). The decrease in the intake manifold pressure is accomplished by adjusting the throttle valve(14). An Independent claim is also included for a fuel recovery system for an internal combustion engine including purgable cannister for trapping fuel vapors.