What are the reasons for a car stalling without pressing the accelerator?
2 Answers
Reasons for a car stalling without pressing the accelerator may include fuel line blockage, throttle blockage, spark plug failure, sensor malfunction, etc. Below is a detailed introduction about the car throttle: 1. Overview: The throttle is a controllable valve that regulates the air entering the engine. After the air enters the intake pipe, it mixes with gasoline to form a combustible mixture, which then burns to produce work. Connected to the air filter on top and the engine block below, it is known as the throat of the car engine. 2. Classification: Throttles are divided into traditional cable-operated and electronic throttle types. In traditional engines, the throttle control mechanism operates via a cable (soft steel wire) or rod, with one end connected to the accelerator pedal and the other to the throttle linkage plate. Electronic throttles mainly use throttle position sensors to control the throttle opening angle based on the engine's required energy, thereby regulating the amount of air intake.
Oh, I've seen many cases where the car stalls when not pressing the accelerator. The most common issue is a malfunction in the idle speed control system. For example, in older cars, the idle air control valve gets too clogged with carbon deposits and can't maintain RPM when the throttle is slightly released, causing the engine to stall. Another problem is a dirty or blocked air filter, which prevents the engine from getting enough air, making it too weak to idle. Even worse is a fuel system failure, such as clogged fuel injectors or an aging fuel pump, where fuel supply can't meet demand, suddenly cutting off the power source. Additionally, faulty sensors like the throttle position sensor or mass airflow sensor send incorrect signals, confusing the ECU and causing RPM to drop. Loose or corroded electrical connections also contribute to unstable operation. This is a major safety hazard—if the car stalls at an intersection, it's highly prone to rear-end collisions. I recommend not driving the car and taking it to a repair shop immediately for a thorough inspection of all idle-related components.
