Glossary “vapor lock” Definition:
Condition in carbureted engines where excessive heat has caused the fuel in the fuel line or fuel pump to boil, blocking the flow of fuel to the carburetor and preventing the engine from running or starting.

Glossary “vapor recovery system” Definition:
1). Part of the EVAP emissions control system that prevents fuel vapors from escaping to the atmosphere by trapping them in the charcoal canister to be drawn into the engine and burned when the engine is running. 2). The provisions of a fuel nozzle that prevent fuel vapors from entering the atmosphere when a vehicle is being fueled.

Glossary “vapor return line” Definition:
Hose or line used to carry fuel vapor from the fuel pump or the liquid vapor separator back to the fuel tank.

Glossary “vapor saver system” Definition:
Term used for vapor recovery system.

Glossary “vapor liquid ratio” Definition:
Measurement of the ratio of vapor to liquid at a given temperature used to help determine a gasoline’s tendency to contribute to vapor lock in an automotive fuel system.

Glossary “vapor lines” Definition:
Lines used to carry gas or vapor.