* Idle Air Control (IAC) Valve: This valve regulates the amount of air entering the engine at idle. A malfunctioning IAC valve can cause the engine to stall or die when the throttle is closed (not giving gas). It might be dirty, stuck, or faulty.
* Throttle Position Sensor (TPS): This sensor tells the engine control unit (ECU) the position of the throttle. A faulty TPS can provide incorrect information, leading to erratic idle and stalling.
* Mass Air Flow (MAF) Sensor: This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can cause incorrect fuel delivery, leading to stalling.
* Vacuum Leaks: A leak in the intake manifold or vacuum lines can disrupt the air/fuel mixture, causing the engine to lose its idle.
* Dirty or Clogged Fuel Injectors: If the injectors are dirty, they may not be delivering enough fuel to maintain idle.
* Spark Plugs and Wires: Worn-out spark plugs or damaged ignition wires can lead to misfires, causing the engine to stumble and die.
* Faulty Crankshaft Position Sensor (CKP) or Cam Position Sensor (CMP): These sensors tell the ECU where the engine is in its rotation. Faulty signals from these sensors can cause the engine to shut down.
* Low Fuel Pressure: Insufficient fuel pressure can prevent the engine from running smoothly at idle.
* Battery Issues (Less Likely): While less likely to cause an immediate shutoff at idle *unless* the battery is extremely weak, a failing battery can cause voltage drops that affect the engine's ability to run properly.
It's crucial to get this diagnosed by a mechanic. Trying to troubleshoot this yourself without the proper tools and knowledge could lead to further damage. A mechanic can use diagnostic tools to identify the specific problem and provide the necessary repair. Simply describing the symptom ("car shuts off when not giving gas") is not enough information for a definitive diagnosis.
