* The engine's owner's manual: This is the most reliable source of information.
* A reputable automotive repair manual: These manuals typically provide detailed information on engine specifications, including firing order.
* Online resources: You can search for the engine model number online, and you may find information on websites dedicated to automotive repair or specific car models.
Please note that providing incorrect information about firing order can be dangerous and lead to engine damage. It is crucial to get accurate information from a reliable source.