What Causes Engine Stalling and Shaking at Idle?
2 Answers
The causes of engine stalling and shaking at idle are varied. Issues with any component in the intake system, ignition system, or fuel system can lead to this phenomenon. Specific reasons include: 1. Sudden fuel cutoff or ignition failure in the engine. 2. Unstable performance of the engine control circuit or related control components. 3. Excessive engine carbon buildup or throttle blockage, which reduces engine power, resulting in uneven power output and gradual attenuation. How to handle idle stalling: 1. When idle stalling occurs, first adjust the idle speed based on the actual situation. 2. If the issue resolves after adjustment, it indicates improper idle screw adjustment. If the issue persists, slightly open the throttle to maintain engine operation, then check for air leaks at the carburetor or intake pipe gasket using cotton yarn or paper strips. If no leaks are found, inspect the idle jet, clean the idle fuel passage, and reassemble for testing. If the issue resolves, it indicates a blockage in the idle jet or idle fuel passage.
I've been driving for over twenty years and have encountered several instances of idle shaking followed by stalling. It feels like the car is trembling before suddenly going silent. This is usually related to the intake system, such as excessive carbon buildup in the throttle body blocking the airflow, which makes it hard for air to enter the engine, leading to shaking and stalling. Alternatively, issues with the ignition system, like worn-out spark plugs failing to ignite, can cause incomplete combustion of the air-fuel mixture, making the car shudder to a stop. Fuel system problems, such as clogged fuel injectors or an unstable fuel pump, can also lead to this. Faulty sensors, like a stuck idle control valve that fails to regulate RPM, can cause erratic idling and stalling. Carbon buildup in the intake manifold can also result in unstable idling, and poor fuel quality may trigger shaking. Minor issues like vacuum hose leaks can disrupt the air-fuel mixture ratio. If you notice this problem, don't delay—I recommend getting it checked at a reputable shop immediately. Ignoring it could damage the engine or even leave you stranded on the road, which is too risky. Regular throttle body cleaning and spark plug replacements can help prevent these issues.
