What Are the Causes of a Lean Air-Fuel Mixture in Cars?

[StCarmen]

Introduction to the causes of a lean air-fuel mixture in cars: In terms of the fuel system, a lean mixture essentially means insufficient fuel supply, resulting in a lower proportion of gasoline in the mixture. Insufficient fuel supply can be categorized into two types of faults: those outside the carburetor and those within the carburetor. Below are the detailed explanations: 1. Main causes of insufficient fuel supply outside the carburetor: (1) The fuel filter is clogged. (2) There is a blockage in the fuel line or the fuel pipe is damaged. (3) Loose or leaking fuel pipe connections. 2. Main causes of insufficient fuel supply within the carburetor: (1) The carburetor's fuel inlet is clogged, preventing smooth fuel flow from the external fuel system into the float chamber. (2) The float chamber fuel level is too low or the float is stuck. (3) The needle valve is stuck or other fuel outlets are clogged. (4) The main jet is clogged or improperly adjusted. Additionally, leaks in the intake manifold gasket or the carburetor base gasket can also cause the air-fuel mixture to become too lean.