| 摘要 |
<p>An evaporative emission control system (10) for a turbocharged engine (11). The evaporative emission control system (10) includes a fuel vapor canister (18) in fluid communication with an intake manifold (22) of the turbocharged engine (11), a purge valve (26) positioned between the intake manifold (22) and the fuel vapor canister (18), a bypass valve (38) positioned between the purge valve (26) and the fuel vapor canister (18) and connected to the atmosphere, and an evaporative system (10) integrity monitor operable to seal the canister (18) from the atmosphere when the engine (11) is off. In operation, the evaporative system (10) integrity monitor is closed so as to seal the fuel vapor canister (18) from the atmosphere, the purge valve (26) is closed so as to isolate the intake manifold (22) from the fuel vapor canister (18), and the bypass valve (38) is opened so as to connect the fuel vapor canister (18) to the atmosphere. Proper operation of the evaporative system integrity monitor is determined if the evaporative system integrity monitor toggles from closed to open when a vacuum in the fuel vapor canister (18) reaches a predetermined level.</p> |
