Vehicles using 12SC engine list:

Engine 12SC

Symptoms:
- Rough idling and stalling, especially when cold
- Loss of power and poor acceleration
- Increased fuel consumption
- Engine misfires or hesitation during throttle response
- Occasional difficulty starting the engine

Diagnosis:
- Check ignition components such as spark plugs, distributor cap, rotor, and ignition wires for wear or damage
- Inspect carburetor or fuel injection system for clogging or improper adjustment
- Test for vacuum leaks around intake manifold and hoses
- Verify timing settings and adjust if necessary
- Examine air filter condition and replace if dirty or clogged

Fixes:
- Replace worn spark plugs and ignition components to ensure proper spark delivery
- Clean and adjust carburetor or fuel injection system for optimal fuel-air mixture
- Repair or replace cracked or leaking vacuum hoses to eliminate air leaks
- Reset ignition timing to manufacturer specifications to improve combustion efficiency
- Replace air filter regularly to maintain airflow and engine performance

Prevention:
- Perform routine maintenance including timely replacement of spark plugs and ignition parts
- Regularly clean or service carburetor/fuel injection components to prevent clogging
- Inspect vacuum lines periodically for cracks or leaks and replace as needed
- Maintain proper engine timing during scheduled servicing
- Change air filter according to service intervals to avoid restricted airflow

By following these diagnostic steps and maintenance practices, owners of vehicles equipped with the 12SC engine can minimize common issues and ensure reliable engine performance.