What is vapour Lock?

In an internal combustion engine, vapour lock occurs when the liquid fuels convert to vapours or bubble before entering into the fuel rail or carburetor. This is a major problem because pumps are made for liquid, not for vapour.

Because of the excessive heat of the engine in hot weather or vehicles operating at high altitude, the boiling point of the fuel decreases and they become vapour.

As a result, the mentioned problem occurs: -

• Loss of fuel pressure (and flow)
• Loss of power
• Stalling
• Difficulty restarting the engine