System Inspection
1. Visually inspect the components of the ignition system for:^ Damaged or worn distributor cap and rotor
^ Damaged spark plugs
^ Improperly seated spark plug, distributor cap, or rotor
^ Corroded, contaminated, or carbon fouled distributor cap
^ Discharged battery
^ Damaged, loose connectors
^ Damaged insulation
^ Poor coil, distributor, and spark plug connections
^ Blown fuses
2. Check the vehicle's maintenance schedule to ensure that the spark plugs have been properly maintained/replaced every 60,000 miles.
3. Check the spark plug wires and boots for signs of poor insulation that could cause cross firing.
4. Check for a damaged or worn timing belt, which can cause symptoms that appear to be timing related.
5. Make sure the engine idle speed and base timing are within specification.