Why Does the Engine Stall at Idle?
2 Answers
Here are the reasons why the engine stalls at idle: 1. Circuit failure: The engine stalls due to low-voltage power failure while driving. A short circuit in the low-voltage circuit causes intermittent stalling. Check the vehicle's low-voltage circuit, ignition and starter switch, and fuse box. 2. Component failure: Usually related to the ignition coil, capacitor, or electronic ignition module. The engine may start initially but stall after a while, then restart and stall again. 3. Fuel system failure: Damaged fuel pump, cracked fuel line, clogged carburetor fuel inlet, or empty fuel tank. In such cases, the car is difficult to restart. 4. Ignition system: Engine overheating or issues with the anti-explosion system can also cause stalling.
I've noticed that when a car suddenly stalls at idle, it's quite a common issue, mainly due to excessive carbon buildup in the throttle body, which blocks the air passage, causing the engine to suffocate. It could also be an unstable fuel supply from the fuel pump, where insufficient pressure at low speeds leads to stalling. If the spark plugs are worn or dirty, the ignition becomes weak, making it prone to misfiring at idle. Additionally, sensors like the idle control valve or throttle position sensor, if faulty, can confuse the car's computer about how to adjust the engine speed, resulting in a stall. I've dealt with this problem before; cleaning the throttle body and checking the fuel filter often helps, but for severe cases, it's best to visit a professional repair shop because stalling at traffic lights is too dangerous. Other minor culprits could be a clogged air filter or loose electrical wiring.
