The function of the gasoline pump is to draw the gasoline out of the tank and press it into the float chamber of the carburetor through the pipeline and the fuel filter. It is because of the gasoline pump that the fuel tank can be placed at the rear of the car far from the engine and lower than the engine.
Gasoline pumps can be divided into mechanically driven diaphragm type and electric driven type according to different driving methods.
The electric gasoline pump does not rely on the camshaft, but repeatedly draws the pump membrane by electromagnetic force. This electric pump is free to choose the installation position and prevent air resistance.
The main installation type of the electric gasoline pump for gasoline-injected engines is either installed in the oil supply line or in the fuel tank. The former has a large layout range, and it is not necessary to specially design a fuel tank, which is convenient for installation and disassembly. However, the oil pump has a long suction section, is prone to generate air resistance, and has a large working noise. In addition, the oil pump must not be leaked. This type of vehicle is rarely used in current new vehicles. The latter has a simple fuel line, low noise, and low fuel leakage requirements, which is the current main trend.
In operation, in addition to the fuel consumption required to operate the engine, the flow rate of the gasoline pump should also ensure sufficient return flow to ensure stable pressure and adequate cooling of the fuel system.