1. Consult your owner's manual: This is the most reliable source. The firing order should be printed in it.
2. Check a Ford service manual: A Haynes or Chilton manual for your specific year and model will show a detailed diagram of the engine, including the correct spark plug wire routing.
3. Look for markings on the engine: Sometimes, the firing order is stamped onto the engine block or valve cover itself.
4. Use a reliable online resource: Websites specializing in Ford vehicles, such as Ford forums, may have detailed information for your specific engine. However, always double-check with the owner's or service manual as the most accurate source.
Without this information, providing a firing order is unreliable and could damage your engine. Getting it wrong can lead to misfires and potential engine damage. Please use one of the methods above to determine the correct order for your vehicle.