* Idle Air Control (IAC) Valve: This valve regulates the amount of air entering the engine at idle. A faulty IAC valve is a very common cause of this problem. It might be dirty, sticking, or failing completely.
* Throttle Position Sensor (TPS): This sensor tells the computer the position of your throttle. A faulty TPS can give the computer inaccurate information, leading to an inability to maintain idle.
* Mass Airflow Sensor (MAF) Sensor: This sensor measures the amount of air entering the engine. A dirty or failing MAF sensor can cause erratic idling and stalling.
* Vacuum Leaks: A leak in the vacuum system can disrupt the air-fuel mixture, preventing the engine from idling properly. These leaks can be hard to find and are often in hoses or connections.
* Fuel System Issues: While less likely given your description, problems with the fuel pump, fuel filter, or fuel injectors could also contribute. A weak fuel pump might not supply enough fuel at idle.
* Computer Problems (PCM): In rare cases, the Powertrain Control Module (PCM) itself could be faulty. This is usually diagnosed after other issues are ruled out.
What you should do:
1. Do NOT drive the car: It's unsafe to drive a vehicle that dies when you release the gas pedal.
2. Have it towed to a mechanic: Attempting DIY repairs without experience could worsen the situation. A qualified mechanic can properly diagnose the issue using diagnostic tools.
3. Mention the specific symptom: Clearly explain to the mechanic that the engine only runs when the gas pedal is briefly pressed. This will help them focus their diagnosis.
Trying to guess and replace parts without proper diagnosis could be expensive and ineffective. Professional help is needed to safely and efficiently resolve this problem.
