High-Probability Causes:
* Idle Air Control Valve (IACV): This valve regulates the amount of air entering the engine at idle. A dirty or malfunctioning IACV can lead to inconsistent idling and stalling. Cleaning the IACV is often a simple and inexpensive first step. If cleaning doesn't work, replacement might be necessary.
* Throttle Position Sensor (TPS): This sensor tells the computer the position of the throttle. A faulty TPS can provide incorrect information, leading to improper fuel delivery and stalling, especially at idle. Testing with a multimeter is necessary to diagnose a faulty TPS.
* Mass Airflow Sensor (MAF) Sensor: Though less likely to cause stalling *only* at idle, a dirty or failing MAF sensor can provide inaccurate readings of air intake, leading to poor fuel mixture and potentially stalling, especially if the engine is already struggling at low RPM. Cleaning the MAF sensor (carefully!) is worth a try.
* Vacuum Leaks: Small vacuum leaks can disrupt the engine's air/fuel mixture, causing erratic idling and stalling. Inspect all vacuum hoses and connections for cracks, splits, or loose fittings. Pay close attention to hoses connected to the brake booster, as a leak there can cause idling problems.
Less-Likely but Still Possible Causes:
* Fuel Delivery Issues: A weak fuel pump, clogged fuel filter, or problems with the fuel injectors could contribute to stalling, but these are usually more noticeable under load as well.
* Ignition System Problems: Worn spark plugs, faulty ignition wires, or a failing distributor (if equipped) can cause misfires, especially under low-load conditions.
* Computer (ECU) Issues: A malfunctioning Engine Control Unit (ECU) is less likely, but possible. This is generally diagnosed through more advanced diagnostic tools.
Troubleshooting Steps:
1. Check the basics: Ensure the battery is fully charged and the terminals are clean and tight.
2. Clean the IACV: This is the easiest and cheapest fix to try first. There are many online tutorials showing how to do this.
3. Inspect Vacuum Hoses: Carefully examine all vacuum hoses for cracks, leaks, or loose connections.
4. Clean the MAF Sensor: Use a MAF sensor cleaner (not ordinary cleaner) and follow the instructions carefully.
5. Check the TPS: This requires a multimeter and some technical knowledge. If you're not comfortable with this, take it to a mechanic.
6. Check Spark Plugs and Wires: Inspect for wear, damage, or corrosion. Replacement might be necessary.
When to see a mechanic:
If you're uncomfortable performing these checks yourself, or if the problem persists after attempting these fixes, it's best to take your Paseo to a qualified mechanic for diagnosis and repair. They have the tools and expertise to diagnose more complex issues like a faulty ECU or fuel system problems. Mention the specific symptoms (stalling only at idle) to help them pinpoint the problem.
