1. Spark Plug Wires: Faulty spark plug wires can cause the engine to misfire, especially when exposed to moisture. Check the spark plug wires for cracks or damage, and replace any that are worn out.
2. Distributor Cap and Rotor: The distributor cap and rotor are responsible for distributing electrical current to the spark plugs. If they are cracked or damaged, they can cause misfires and rough running. Check these components for signs of wear and replace them if necessary.
3. Ignition Coil: The ignition coil provides power to the spark plugs. If the coil is faulty, it can cause misfires and rough running. Check the ignition coil and replace it if necessary.
4. Fuel Filter: A clogged fuel filter can restrict the flow of fuel to the engine, causing it to run rough. Replace the fuel filter according to the manufacturer's recommendations.
5. Air Filter: A dirty air filter can restrict airflow to the engine, causing it to run rough. Check the air filter and replace it if necessary.
6. Throttle Body: The throttle body controls airflow into the engine. If the throttle body is dirty, it can cause the engine to run rough. Clean the throttle body and check the throttle position sensor to ensure it is functioning properly.
7. Fuel Injectors: Dirty or faulty fuel injectors can cause the engine to run rough and misfire. Have the fuel injectors cleaned and tested to determine if they need to be replaced.
If you have checked all of these potential causes and are still experiencing rough running in the rain, it is recommended to have your vehicle diagnosed by a qualified mechanic.
