Systems and methods for onboard canister purge valve flow mapping

A system for a hybrid vehicle, comprising:

• a fuel vapor storage canister positioned in an evaporative emissions system of the hybrid vehicle, the fuel vapor storage canister selectively fluidically coupled to a fuel system via a fuel tank isolation valve and selectively fluidically coupled to an intake of an engine via a canister purge valve;
• a throttle positioned in the intake of the engine;
• a plurality of intake valves configured to regulate air flow to the engine;
• a mass air flow sensor positioned in the intake of the engine;
• and
• a controller with computer readable instructions stored on non-transitory memory that when executed, cause the controller to:
• with the engine not combusting air and fuel, in a first condition, operate the evaporative emissions system in a first mode to direct a first test flow that is negative with respect to atmospheric pressure to the intake and indicate evaporative emissions system degradation in response to the first test flow being outside of a first predetermined threshold of a first baseline flow obtained via operating the evaporative emissions system in the first mode, where the first test flow and first baseline flow are indicated via the mass air flow sensor;
• and
• in a second condition, operate the evaporative emissions system in a second mode to direct a second test flow that is positive with respect to atmospheric pressure to the intake and indicate evaporative emissions system degradation in response to the second test flow being outside of a second predetermined threshold of a second baseline flow obtained via operating the evaporative emissions system in the second mode, where the second test flow and the second baseline flow are monitored via the mass air flow sensor.