2. Change the spark plug wires. Old spark plug wires can also cause misfires. Replace your spark plug wires with new ones every 60,000 miles.
3. Change the oil and filter. Dirty oil can clog up your engine and cause it to run poorly. Change your oil and filter every 3,000 miles or as recommended by your owner's manual.
4. Clean the throttle body. A dirty throttle body can cause your engine to idle rough and stall. Clean the throttle body with a throttle body cleaner every 15,000 miles.
5. Clean the MAF sensor. A dirty MAF sensor can cause your engine to run lean or rich. Clean the MAF sensor with a MAF sensor cleaner every 15,000 miles.
6. Check the fuel pressure. Low fuel pressure can cause your engine to run rough or stall. Check the fuel pressure with a fuel pressure gauge and compare it to the specifications in your owner's manual.
7. Check the ignition timing. The ignition timing is important for ensuring that the spark plugs fire at the correct time. Check the ignition timing with a timing light and compare it to the specifications in your owner's manual.
8. Adjust the valve lash. The valve lash is the clearance between the valve stem and the rocker arm. If the valve lash is too tight, the valves will not open properly and your engine will lose power. If the valve lash is too loose, the valves will make noise and your engine will run rough. Adjust the valve lash according to the specifications in your owner's manual.
9. Replace the PCV valve. The PCV valve helps to remove harmful gases from the engine. A bad PCV valve can cause your engine to run rough or stall. Replace the PCV valve every 30,000 miles.
10. Check the vacuum lines. Vacuum leaks can cause your engine to run lean or rich. Check the vacuum lines for cracks or breaks and replace any damaged lines.
