This service repair manual covers Mercury Mercruiser #22 Marine Engines, specifically the IN-LINE Diesel models, including the D2.8L D-Tronic and D4.2L D-Tronic variants. These turbocharged, in-line diesel engines feature D-Tronic electronic diesel injection and are designed for marine applications, available with Sterndrive (MCM) or Inboard (MIE) drive options. The manual details engine specifications, systems, and maintenance schedules for these robust and reliable marine powerplants. This comprehensive 878-page English-language manual provides detailed step-by-step instructions for repair, service, restoration, maintenance, and diagnosis. It is intended for professional technicians, mechanics, workshops, and DIY individuals seeking to understand and maintain their Mercury Mercruiser marine engines. Coverage includes electrical, fuel, cooling, intake/exhaust, drive, and steering systems, as well as troubleshooting guidance and technical specifications, ensuring optimal performance and longevity of the D2.8L and D4.2L D-Tronic engines.