* Idle Air Control (IAC) Valve: This valve regulates airflow at idle. A dirty or malfunctioning IAC valve can cause the engine to stall when idle speed drops, such as when you stop.
* Throttle Position Sensor (TPS): The TPS tells the computer the throttle's position. A faulty TPS can provide incorrect data, leading to the engine cutting out at idle.
* Mass Airflow Sensor (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.
* Crankshaft Position Sensor (CKP) Sensor: This sensor tells the computer the engine's rotational position. A failing CKP sensor can cause the engine to misfire or stall.
* Cam Position Sensor (CMP) Sensor: Similar to the CKP sensor, a faulty CMP sensor can disrupt the engine's timing and lead to stalling.
* Fuel Pump: A weak or failing fuel pump might not supply enough fuel at low engine speeds, causing the engine to stall.
* Vacuum Leaks: Leaks in the vacuum system can disrupt engine operation and lead to stalling.
* Battery/Alternator: A weak battery or a failing alternator can cause voltage drops, leading to the engine cutting off.
* Transmission Issues (Automatic): In some cases, a problem within the automatic transmission can cause the engine to stall, though this is less common.
* Programming/Software Issues (ECM/PCM): In rare instances, a problem with the engine control module's programming might be responsible.
Troubleshooting Steps:
1. Check the battery and alternator: Test the battery voltage and have the alternator checked.
2. Inspect the air filter: A clogged air filter can restrict airflow, leading to stalling.
3. Check for vacuum leaks: Visually inspect vacuum lines and connections for cracks or disconnections.
4. Have a professional diagnose the issue: The most reliable way to pinpoint the problem is to take your Suburban to a qualified mechanic. They have the tools and expertise to diagnose the issue accurately.
It's important to not ignore this problem. Continuing to drive with an engine that stalls could lead to more serious issues and potentially dangerous situations. Professional diagnosis is strongly recommended.
