- Faulty temperature sensor: If the temperature sensor is defective, it may send incorrect signals to the engine control module (ECM), causing the engine to run rich or lean, which can lead to poor idling and stalling.
- Idle air control (IAC) valve problems: The IAC valve controls the amount of air that bypasses the throttle plate at idle. A dirty or faulty IAC valve can cause the engine to idle too high or too low and stall when the engine is warm.
- Vacuum leaks: Vacuum leaks can cause the engine to run lean, leading to poor idling and stalling. Check the vacuum hoses and connections for any cracks or leaks.
- Fuel system problems: A weak fuel pump, clogged fuel filter, or faulty fuel injector can cause the engine to run lean or rich, which can lead to stalling.
- Weak ignition system: A weak spark plug or ignition coil can cause the engine to misfire, leading to rough idling and stalling.
- Engine Coolant Temperature Sensor: A faulty temperature sensor can send inaccurate readings to the vehicle's computer, resulting in the computer not properly regulating fuel mixture and ignition timing. This can cause the engine to run rich or lean when the engine is warm, leading to poor idling and potentially stalling.
- Catalytic Converter: A clogged or faulty catalytic converter can restrict exhaust flow and cause the engine to run poorly when warm. This is because the catalytic converter helps to convert harmful pollutants into less harmful compounds, and when it is clogged, it can cause the engine to run inefficiently and stall when at operating temperatures.
- Fuel Injectors: Fuel injectors spray fuel into the engine's cylinders, and when they become clogged or dirty, they can deliver an insufficient amount of fuel, causing the engine to run lean and potentially stall.
It is recommended that you have your van inspected by a qualified mechanic to accurately diagnose and resolve the issue.
