FAA AMT (Aviation Maintenance Technician) Airframe Practice Exam

The fuel pressure warning signal on most aircraft engines is usually taken from the fuel pressure line of the carburetor. This is because the fuel pressure line is the most direct and accurate measurement of fuel pressure. If the pressure is too low, it could indicate a clogged fuel line, while too high pressure could indicate a faulty fuel pump. This option is more accurate than the other choices listed because the intake manifold can sometimes have inconsistent pressure readings, the engine fuel injector measures pressure after the fuel has already passed through multiple components, and the fuel tank outlet measures the pressure at the very beginning of the fuel flow process, which may not accurately reflect the pressure throughout the engine.