What does a fuel pressure gauge measure?

A fuel pressure gauge is specifically designed to measure the fuel pressure within the fuel system of a vehicle. This is important for diagnosing various engine performance issues, as proper fuel pressure is crucial for optimal engine operation. If the fuel pressure is too low, it can lead to insufficient fuel delivery, causing the engine to run rough or stall. Conversely, if the pressure is too high, it can cause excessive fuel flow, leading to flooding and poor fuel economy.

Understanding the fuel pressure is vital for ensuring that the fuel injectors are receiving the correct amount of fuel to create the necessary air-fuel mixture for efficient combustion. This gauge provides direct feedback on the health of the fuel pump, fuel lines, and fuel filter, helping technicians assess whether components are functioning properly. The other options, while related to fuel systems in some way, do not directly pertain to what a fuel pressure gauge specifically measures.