This service manual provides detailed instructions for the maintenance, troubleshooting, and repair of the Isuzu 4JG2 diesel engine. It covers all essential components, including the fuel system, cooling system, lubrication system, and electrical system. The manual offers step-by-step procedures for disassembly, inspection, reassembly, and adjustments, along with detailed diagrams and technical specifications to aid in accurate repairs. It also includes routine maintenance schedules and safety guidelines to ensure optimal engine performance and longevity. This manual is a crucial resource for mechanics and technicians responsible for the upkeep of the Isuzu 4JG2 engine.