Is a Lean Fuel System Caused by Fuel Quality Issues?
1 Answers
A lean fuel system is not solely caused by fuel quality issues. Excessive carbon buildup on valves and fuel injectors, damaged mass airflow sensors, and intake system leaks can also lead to a lean fuel system. A lean fuel system is an alarm signal triggered by the engine's oxygen sensor detecting incomplete gasoline combustion. This alarm occurs due to insufficient fuel injection combined with excessive air, resulting in a low concentration of combustible gas. Therefore, addressing this issue requires consideration from two aspects. First, fuel system problems, including clogged fuel injectors due to excessive carbon buildup or insufficient fuel supply caused by a faulty fuel pump. On the other hand, intake system failures, such as a malfunctioning mass airflow sensor or intake leaks, can lead to inaccurate air supply. It is recommended that vehicle owners visit a repair facility to read fault codes using a diagnostic scanner and systematically troubleshoot the issue based on the prompts. A lean fuel system can result in reduced engine power, increased fuel consumption, and in severe cases, engine stalling and difficulty starting. It also causes elevated idle speed, where the engine RPM struggles to drop to idle speed quickly when decelerating. In such cases, removing the spark plugs will reveal white-colored electrodes, confirming an excessively lean air-fuel mixture.
