Fuel vapor purging diagnostics
AssigneeFord Global Technologies, LLC
InventorsRoss Dykstra Pursifull, Allan J. Lippa, John D. Russell, Gopichandra Surnilla, Joseph Norman Ulrey
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Abstract
Systems and methods are provided for monitoring reverse flow of fuel vapors and/or air through a vehicle fuel vapor recovery system, the fuel vapor recovery system coupled to an engine intake of a boosted internal combustion engine. One example method comprises, intermittently adjusting a restriction in the fuel vapor recovery system during boosted conditions, and indicating degradation based on one or more of a change in a pressure value, or based on a change in flow in the fuel vapor recovery system.
Claims22
1-21. (canceled)
A method for a vehicle fuel vapor system coupled to an engine intake, comprising:
- during boosted conditions, intermittently adjusting a canister vent valve of a canister, a check valve positioned between the engine intake and the canister;
- and
- indicating degradation, including reverse flow of gases from the engine intake to the fuel vapor system, based on a change in a pressure value in the fuel vapor system that correlates to the intermittent adjusting.
A system, comprising:
- an engine comprising an intake;
- a boosting device with a compressor configured to provide a boost to the engine intake;
- a fuel vapor system coupled to the engine intake, said fuel vapor system including a fuel tank pressure transducer, a fuel vapor canister, a canister purge valve, a check valve and a canister vent valve;
- and
- a control system configured to,
- intermittently adjust a restriction in the fuel vapor system during a boosted condition;
- and
- indicate degradation, including reverse flow of gases from the engine intake to the fuel vapor system, based on a change in pressure value in the fuel vapor system that correlates to the intermittent adjusting.
Dependencies are inferred from the claim text.