The mechanical fuel pump is a component in an internal combustion engine that plays a crucial role in delivering fuel from the fuel tank to the carburetor or fuel injection system. Here are the key purposes and functions of a mechanical fuel pump:

1. Fuel Transfer:

   • The primary purpose of a mechanical fuel pump is to transfer fuel from the fuel tank to the engine. It draws fuel from the tank and delivers it to the carburetor or fuel injection system, ensuring a consistent and controlled flow of fuel.

2. Pressure Generation:

   • Mechanical fuel pumps are designed to generate the necessary fuel pressure for the engine's combustion process. The fuel needs to be pressurized to atomize properly and mix with air in the combustion chamber for efficient burning.

3. Carbureted Engine Supply:

   • In vehicles with carbureted engines, the mechanical fuel pump supplies fuel directly to the carburetor, where it mixes with air to form a combustible mixture. This mixture is then drawn into the engine cylinders for combustion.

4. Fuel Injection System Support:

   • In some older vehicles and small engines, mechanical fuel pumps are used to supply fuel to mechanical fuel injection systems. However, it's essential to note that many modern vehicles use electric fuel pumps for fuel injection.

5. Engine Vacuum Operation:

   • Many mechanical fuel pumps are driven by engine vacuum or a mechanical linkage connected to the camshaft. The engine's mechanical motion or vacuum pressure is used to operate the diaphragm inside the fuel pump, creating suction and pressure.

6. Simple Design and Reliability:

   • Mechanical fuel pumps have a relatively simple design, consisting of a diaphragm, a spring, and a set of valves. This simplicity contributes to their reliability and ease of maintenance.

7. Mechanical Action:

   • The mechanical fuel pump operates based on the mechanical motion of the engine. When the engine is running, the pump's diaphragm moves, creating suction to draw fuel from the tank and pressurizing it for delivery to the engine.

8. Cost-Effectiveness:

   • Mechanical fuel pumps are often more cost-effective than electric fuel pumps. Their simplicity in design and operation contributes to lower manufacturing and maintenance costs.

It's important to note that while mechanical fuel pumps were more common in older vehicles with carbureted engines, many modern vehicles, especially those with fuel injection systems, use electric fuel pumps. Electric fuel pumps are better suited for the higher pressure requirements of fuel injection systems and are commonly found in modern fuel delivery systems. However, mechanical fuel pumps are still utilized in specific applications, particularly in some smaller engines and certain classic or vintage vehicles.