Fuel System Issues:
* Low fuel: Sounds obvious, but check your fuel gauge.
* Clogged fuel filter: Restricts fuel flow, especially at idle when demand is lower.
* Faulty fuel pump: May not be delivering enough fuel at low engine speeds.
* Dirty fuel injectors: Clogged injectors can prevent proper fuel delivery.
* Vacuum leaks in the fuel system: Can disrupt fuel pressure and mixture.
Ignition System Problems:
* Weak spark: A failing ignition coil, spark plugs, or wires can lead to misfires, especially at idle when the spark needs to be strong.
* Failing ignition control module (ICM): Controls the spark timing and could be malfunctioning.
* Distributor cap and rotor (if applicable): Wear and tear can cause poor spark delivery.
Air Intake System Problems:
* Vacuum leaks in the intake manifold: Lean air/fuel mixture, causing stalling.
* Dirty air filter: Restricts airflow, leading to a lean mixture.
* Mass airflow sensor (MAF) issues: Provides incorrect air flow data to the engine computer.
* Throttle position sensor (TPS) problems: Provides incorrect throttle position data, affecting fuel mixture.
Other Potential Causes:
* Idle air control valve (IACV): Regulates air flow at idle. A malfunctioning IACV can cause stalling.
* Faulty crankshaft position sensor (CKP): Provides information about engine speed and position to the engine control unit (ECU).
* Low battery voltage: Insufficient power to the ignition system.
* Engine coolant temperature sensor (ECT): Incorrect temperature readings can disrupt fuel mixture.
* Improperly adjusted valves: If the valves are not properly adjusted, the engine may not run smoothly at idle.
To help me narrow down the possibilities, please tell me:
* What kind of vehicle is it? (Make, model, year)
* How long has this been happening?
* Does it stall immediately when you come to a stop, or after idling for a while?
* Are there any other symptoms? (e.g., rough running, hesitation, check engine light on)
* Have you recently done any maintenance or modifications?
Providing this information will greatly assist in diagnosing the problem. Ignoring a stalling engine can lead to more significant problems, so it's important to address it promptly. If you are not comfortable working on your vehicle yourself, take it to a qualified mechanic.
