This factory service repair manual provides comprehensive information for Mazda vehicles equipped with the BP-DOHC engine, covering various production years. The BP-DOHC engine is a 1.8L inline 4-cylinder unit featuring DOHC valvetrain and typically utilizing multi-port fuel injection and liquid cooling. While horsepower and torque vary by specific application and tuning, this engine is known for its engineering and reliability. This manual is designed to assist in understanding and maintaining these robust powerplants. The purpose of this English-language manual is to serve as a definitive guide for owners, mechanics, and technicians. It includes detailed step-by-step instructions for disassembly and servicing, advanced troubleshooting guides, comprehensive maintenance checklists, and critical technical specifications, including tightening torques. With detailed illustrations, drawings, photos, and clear warnings, this manual enables users to perform servicing and repairs effectively, potentially leading to significant labor cost savings and empowering DIY capabilities. Wiring diagrams and service procedures for components like the alternator and regulator are also covered.