🏷️ Basic Information Identification Make: Jeep Manufacturer: Chrysler Motors Year: 1990 Codes Chassis Codes: XJ (Cherokee), YJ (Wrangler), ZJ (Grand Cherokee - early production, though primarily 1993MY onwards) Engine Codes: Various, including 2.5L AMC I4, 4.0L AMC I6, 4.2L AMC I6 (potentially phased out or limited availability in 1990) 👋 Introduction Market Position Positioning: Jeep vehicles in 1990 were positioned as robust, capable off-road vehicles and practical utility vehicles. The Cherokee (XJ) was a pioneer in the compact SUV segment, known for its unibody construction and legendary four-wheel-drive systems. The Wrangler (YJ) continued the legacy of the CJ series with its iconic open-air, go-anywhere design. The Grand Cherokee (ZJ), introduced later in the decade, aimed at a more premium segment of the SUV market. Competitive Analysis Competitors: In 1990, the Cherokee competed with vehicles like the Ford Bronco II, Chevrolet S-10 Blazer, and Toyota 4Runner. The Wrangler competed primarily against itself as the segment leader and other niche off-roaders. The upcoming Grand Cherokee would face competition from luxury SUVs such as the Lincoln Navigator and Cadillac Escalade, and established players like the Range Rover and Mitsubishi Montero. Key Features Jeep Cherokee Xj: Compact SUV, unibody construction, strong off-road capability, available 4.0L inline-six engine, spacious interior for its size, practical for daily use. Jeep Wrangler Yj: Body-on-frame construction, removable doors and top, iconic Jeep styling, strong off-road performance, basic amenities, designed for open-air driving and recreation. Manual Purpose: To provide professional automotive technicians with the necessary information to diagnose, maintain, and repair Jeep vehicles manufactured by Chrysler Motors for the 1990 model year, ensuring accuracy and efficiency in service operations. 📋 Manual Details Coverage Areas Region: Primarily North American market, with specifications applicable to global markets where these models were sold. Page Count Estimated Pages: Varies by specific model and engine covered within the collective manual, likely exceeding 1000 pages for comprehensive coverage. This is a workshop manual, typically extensive. Manual Type Type: Workshop Service Repair Manual Language Language: English Format Format: Downloadable (digital format, likely PDF) 📖 Manual Coverage Systems Covered Powertrain: Engine mechanical (4.0L I6, 2.5L I4), fuel system (injection and carburetion where applicable), ignition system, exhaust system, cooling system, lubrication system, powertrain control module (PCM) and diagnostics. Transmission And Drivetrain: Manual and automatic transmissions (e.g., AX-5, AX-15, AW-4), transfer case operation and repair, front and rear axle assemblies, drive shafts, U-joints, driveline diagnostics and repair. Braking System: Front and rear brake systems (disc and drum), hydraulic system, parking brake, ABS system (if equipped), bleeding procedures, component replacement. Suspension And Steering: Front and rear suspension systems (leaf spring, coil spring, solid axle designs), steering linkage, power steering system, wheel alignment specifications. Electrical System: Battery, charging system (alternator), starting system (starter motor), lighting system, instrumentation, power accessories (windows, locks), wiring diagrams, fuse and relay locations, diagnostic procedures for electrical faults. Body And Chassis: Frame construction, body panels, doors, interior trim, HVAC system (heating, ventilation, and air conditioning), glass replacement, body sealing, chassis lubrication. Diagnostics And Troubleshooting: Diagnostic trouble codes (DTCs), symptom-based troubleshooting guides, diagnostic tools and procedures, component testing methods. Procedures Included Routine Maintenance: Oil and filter changes, air filter replacement, spark plug replacement, fluid level checks and top-offs, lubrication points. Component Replacement: Detailed step-by-step instructions for replacing major components like engine parts, transmission units, brake calipers, suspension arms, alternators, starters, fuel pumps, etc. Overhaul And Rebuild: Instructions for overhauling or rebuilding engines, transmissions, transfer cases, and differentials, including torque specifications and assembly sequences. Electrical System Repair: Diagnosis and repair of wiring harnesses, sensors, actuators, and control modules, including interpretation of wiring diagrams. Bodywork And Interior: Procedures for body panel alignment, door adjustments, interior trim removal and installation, HVAC component replacement. Special Tools: Identification and usage instructions for specialized tools required for specific repair or diagnostic procedures. Troubleshooting Electrical: Detailed diagnostic charts and flowcharts for identifying and resolving electrical system faults, including starter, charging, lighting, and accessory issues. Engine Tuning: Procedures for ignition timing adjustment (if applicable, though most systems were distributorless by then or had electronic timing control), fuel system adjustments, and emission control system checks. Technical Depth Depth: Comprehensive. Designed for professional technicians, it provides in-depth diagnostic procedures, detailed component specifications, overhaul instructions, and complete repair sequences, covering everything from basic tune-ups to full engine rebuilds and complex electrical system diagnostics. 📊 Manual Specifications File Format Format: PDF Searchability: Searchable text (assuming a well-produced digital document). Print Quality Quality: High resolution, suitable for printing individual pages or the entire manual for workshop use. Binding Type Binding: N/A (Digital download) Paper Type Paper: N/A (Digital download) Completeness Scope: Complete Workshop Service Repair Manual, covering all aspects of vehicle maintenance and repair for the specified model years and variants. ⚙️ Engine Specifications Primary Engine Engine 4.0L I6: 4.0L (242 ci) AMC I6. Known for its durability, torque, and smooth operation....