Systems and methods for detection and mitigation of liquid fuel carryover in an evaporative emissions system

摘要

Methods and systems are provided for detecting and mitigating the presence of liquid fuel carryover in an evap system of a vehicle in response to a refueling event. In one example, during a first condition, a vacuum pump is activated to pressurize the fuel system responsive to a first fuel tank pressure decay rate being less than a threshold, and responsive to a second fuel tank pressure decay rate being greater than a threshold, the vacuum pump is maintained on until a fuel tank pressure decreases to atmospheric pressure. In this way, liquid fuel carryover can be quickly and accurately diagnosed, such that mitigating actions may be taken to ensure liquid fuel is returned to the tank prior to contacting the adsorbent material within the vapor canister.