🏷️ Basic Information Identification Make: Porsche Model: 928 S4-GT Model Code: 928 Generation: Third Generation (928 S4/GT) Codes Specific Variant: S4-GT 👋 Introduction Market Position Positioning: The Porsche 928 represented a significant departure for Porsche, aiming to be a premium grand tourer with a front-engine, V8 configuration, a departure from their traditional rear-engine sports cars. The S4 and GT variants refined this concept with increased power and luxury. Competitive Analysis Competitors: Competed against high-end GT cars like the Jaguar XJS, Aston Martin Vantage, and certain BMW models of the era. Its unique transaxle design and V8 engine offered a different driving experience. Key Features Gran Touring: Designed for comfortable high-speed cruising over long distances, combining performance with luxury. Transaxle Design: Rear-mounted transaxle for optimal weight distribution, contributing to superior handling characteristics. V8 Engine: The powerful 32-valve V8 engine was a hallmark of the 928, offering smooth acceleration and a distinctive sound. Aerodynamics: Sleek, aerodynamic styling with pop-up headlights, characteristic of Porsche design language of the period. 📋 Manual Details Coverage Areas Primary Focus: Electrical System Diagnostics and Repair Secondary Focus: Electrical Component Troubleshooting, Wiring Harness Repair, Fuse and Relay Identification Page Count Estimated Pages: Detailed wiring diagrams suggest a substantial page count, likely exceeding 150 pages for comprehensive coverage of the electrical system. Manual Type Type: Wiring Diagram Manual / Electrical Troubleshooting Manual Language Language: English (implied by common workshop manuals for this era and market). Format Format: Likely a printable document or PDF. The description emphasizes diagrams and illustrations, consistent with technical manuals. 📖 Manual Coverage Systems Covered Power Distribution: Battery, Alternator, Starter, Charging System, Fuse Boxes, Power Distribution Modules. Ignition System: Ignition Control Unit (DME), Ignition Coils, Spark Plug Wires, Sensors related to ignition timing. Fuel System: Fuel Pump, Fuel Injectors, Fuel Pressure Regulator, Engine Control Unit (DME) inputs/outputs related to fuel delivery. Engine Management: DME control unit, sensors (e.g., MAF, TPS, Knock, O2), actuators, wiring to engine components. Lighting: Headlights (low/high beam), Taillights, Brake Lights, Turn Signals, Interior Lighting, Fog Lights. Instrumentation: Dashboard Gauges (Speedometer, Tachometer, Fuel, Temp), Warning Lights, OBC (On-Board Computer) connections. Comfort Controls: HVAC (Heater, Ventilation, Air Conditioning) blower, climate control panel, seat heating, power windows, mirrors, central locking. Audio And Accessories: Radio/Stereo system, amplifier, speakers, power antenna, cigarette lighter/power outlets, sunroof controls. Braking System: ABS (Anti-lock Braking System) sensors and control module, brake fluid level sensor. Chassis Electronics: Cruise Control System, Immobilizer/Alarm System (if applicable). Procedures Included Troubleshooting: Step-by-step diagnostic procedures for electrical faults, identifying open circuits, short circuits, and ground issues. Repair: Instructions for repairing damaged wiring, replacing connectors, fuses, relays, and electrical components. Component Testing: Guidance on testing the functionality of various electrical components using multimeters and other diagnostic tools. Wiring Diagram Interpretation: Detailed explanations of how to read and understand complex wiring schematics, including wire colors, pinouts, and component locations. Technical Depth Depth: Comprehensive. This manual provides the detailed schematic level information required for in-depth electrical diagnosis and repair, suitable for both professional technicians and advanced DIY enthusiasts with basic electronic knowledge. 📊 Manual Specifications File Format Format Type: Likely PDF or scanned original document. Searchability: If PDF, may be text-searchable depending on creation method. Scanned documents may require OCR for searchability. Print Quality Quality: Dependent on the source. Original factory manuals are typically high-quality prints. Digital reproductions may vary. Binding Type Binding: N/A (for digital format). If printed, likely perfect bound or spiral bound for ease of use in a workshop. Paper Type Paper: N/A (for digital format). Original manuals used durable paper stock for workshop environments. ⚙️ Engine Specifications Primary Engine Type: V8, naturally aspirated Displacement: 4.7 Liters (4664 cc) for S4, 5.0 Liters (4957 cc) for GT Bore X Stroke: S4: 94.0 mm x 84.5 mm; GT: 94.0 mm x 88.0 mm Compression Ratio: S4: 10.0:1; GT: 10.4:1 Valvetrain: DOHC, 4 valves per cylinder Performance Horsepower: S4: ~316 hp (235 kW) at 5500 rpm; GT: ~326 hp (243 kW) at 6000 rpm Torque: S4: ~315 lb-ft (427 Nm) at 3000 rpm; GT: ~339 lb-ft (460 Nm) at 4500 rpm Fuel System Injection: Bosch DME (Digital Motor Electronics) with L-Jetronic or similar sequential fuel injection Fuel Type: Unleaded Premium Gasoline Fuel Pump: Dual electric fuel pumps (common for reliability in this model) Engine Management ECU: Porsche DME control unit 🔧 Transmission Standard Type: 5-speed Manual Transaxle (M28/45 for S4, M28/46 for GT) Optional Type: 4-speed Automatic Transaxle (Tiptronic available on later models, though not explicitly mentioned for S4/GT by this manual) Features Gear Ratios: Specific gear ratios vary by transmission and market, but are designed for strong acceleration and comfortable highway cruising. Fluid Type: Typically SAE 75W-90 synthetic gear oil, specific Porsche A-number may apply. Clutch Type: Hydraulically actuated single dry plate clutch (for manual transmission). 📐 Dimensions Exterior Length: Approx. 4,655 mm (183.3 in) Width: Approx. 1,775...