A fuel rail permeant collection system includes a substantially impermeable enclosure surrounding a fuel rail on an internal combustion engine. Preferably, the enclosure is in communication with air intake means for the engine, for example, the intake manifold or runners from the manifold to the engine cylinders, such that fuel collected by the enclosure can be evaporated and passed into the intake means for combustion by the engine. The system may be included in a vehicle vapor purge circuit from a fuel tank emissions-control canister system.