What is one potential cause of air being present in the fuel lines?

Air being present in the fuel lines can occur when the fuel supply is interrupted, and one common cause of this interruption is running out of fuel. When the fuel tank is empty, the engine continues to draw from the lines, which causes any residual fuel in the lines to be consumed, leading to air being sucked into the system. This air can then travel through the fuel lines, creating conditions such as poor engine performance or stalling since the engine requires a continuous supply of fuel to operate correctly.

If the fuel lines draw air, it affects the fuel pump's ability to deliver the required amount of fuel to the engine, which could lead to various types of engine malfunctions. The importance of maintaining fuel levels is crucial for ensuring the integrity of the fuel system and preventing air from entering the fuel lines.