This is NOT a comprehensive guide, but a general overview. Refer to a repair manual for detailed instructions and torque specifications.
Fuel-Injected Engine Tune-Up (Likely for a '91 Tempo):
1. Inspect and Replace Spark Plugs: This is a crucial part. Remove the old plugs and check the gap (using a spark plug gap tool). Replace them with the correct type and heat range specified in your repair manual. Incorrect gap or type will lead to poor performance.
2. Replace Spark Plug Wires: If the wires show cracks, wear, or are brittle, replace the entire set. Ensure they're correctly routed and securely attached to both the spark plugs and distributor cap (if applicable; some '91 Tempos may have coil-on-plug ignition).
3. Inspect and Clean or Replace the Air Filter: A dirty air filter restricts airflow, affecting performance and fuel economy. Replace it with a new one of the correct type.
4. Inspect and Clean the Throttle Body: Accumulated grime can interfere with throttle response. Use a throttle body cleaner and carefully clean the throttle plate and surrounding areas. Refer to your repair manual for specific instructions. Be cautious not to damage any sensors.
5. Check and Adjust (if necessary) the PCV Valve: This valve helps to vent crankcase gases. A faulty PCV valve can lead to poor performance and engine damage. You might need to replace it.
6. Check and Adjust (if adjustable) the Idle Air Control (IAC) Valve: The IAC valve controls idle speed. This step is more advanced and requires specific tools and knowledge; improper adjustment can cause problems. A repair manual is crucial here. Often, cleaning the IAC valve is sufficient.
7. Check the Fuel Filter: Depending on mileage, you might need to replace the fuel filter. This prevents contaminants from reaching the fuel injectors.
8. Inspect and Replace the Distributor Cap and Rotor (if applicable): If your Tempo has a distributor, check for cracks or carbon tracking on the cap and rotor. Replace them if necessary.
9. Check the Ignition Timing (Advanced Procedure): This requires a timing light and is an advanced procedure. Incorrect timing can severely damage the engine. Only attempt this if you have experience. Again, consult your repair manual.
Other Important Considerations:
* Check all hoses and belts: Look for cracks, leaks, or wear. Replace any damaged components.
* Check all fluids: Ensure you have the correct levels of engine oil, coolant, power steering fluid, brake fluid, and transmission fluid (automatic or manual).
* Battery and charging system: Check the battery terminals for corrosion and ensure the charging system is functioning correctly.
This list is not exhaustive. Again, a repair manual specific to your 1991 Ford Tempo is absolutely essential. It will provide detailed instructions, diagrams, torque specifications, and part numbers to ensure you perform the tune-up correctly and safely. If you are uncomfortable performing any of these tasks, take your car to a qualified mechanic.
