Positioning:
Premium Grand Tourer (GT) in the luxury sports car segment.
Competitors 1984:
Ferrari 400i, Aston Martin V8 Vantage, Jaguar XJS, BMW 6 Series.
Defining Attributes:
Front-engine, rear-wheel drive V8, transaxle layout, advanced (for its time) technology, luxurious interior, excellent long-distance touring capabilities.
Primary Focus:
Electrical System Diagnostics and Repair
Estimated Pages:
Varies by specific diagram set, typically 50-150 pages for comprehensive electrical schematics.
Type:
Electrical System Service Manual / Wiring Diagram Supplement
Format:
Printed Document (implied by description, typically sold as a physical copy or high-quality scan)
Electrical Components:
Engine Control Unit (ECU), Fuel Injection System, Ignition System, Lighting (Headlights, Taillights, Interior), Gauges and Instruments, Power Windows, Power Locks, Sunroof, HVAC Controls, Wiper System, Audio System, Cruise Control, Alarm System (if equipped).
Engine Management Electrical:
ECU functions, sensor inputs (MAP, TPS, CTS, O2), actuator outputs (injectors, ignition coils), troubleshooting ECU faults.
Chassis Electrical:
Power windows, power seats, power mirrors, central locking system, exterior and interior lighting circuits, wiper/washer system, horn.
Instrumentation:
Speedometer, tachometer, fuel gauge, coolant temperature gauge, oil pressure gauge, voltmeter, warning lamps, trip computer (if equipped).
Comfort Systems:
Power seat adjustments, climate control system operation, rear window defroster, heated mirrors (if equipped).
Diagnostic Procedures:
Circuit tracing, troubleshooting common electrical faults, component testing, relay and fuse identification, wiring harness inspection and repair, connector diagnostics.
Wiring Diagrams:
Detailed, color-coded wiring diagrams showing component locations, wire routing, connector pinouts, and fuse/relay assignments.
Fuse And Relay Locations:
Specific identification of all fuses and relays, their amperage ratings, and the circuits they protect.
Depth:
Advanced Diagnostic and Repair, suitable for professional technicians and experienced DIYers with basic electronics knowledge.
Troubleshooting Methodology:
Systematic approach to diagnosing electrical faults using a process of elimination and continuity testing.
Format Details:
N/A (assuming print, but if digital, would be PDF/image scans)
Quality:
High-quality reproductions of original factory diagrams, designed for clarity and readability.
Binding:
Likely a stapled booklet or comb-bound for ease of use during repairs.
Paper Quality:
Durable paper stock suitable for workshop environments, often larger format for diagram clarity.
Source:
Original Porsche factory documentation, often reprinted by specialist automotive publishers.
Engine Type:
V8, naturally aspirated
Displacement:
4.7 Liters (4664 cc)
Bore X Stroke:
95.0 mm x 83.3 mm
Compression Ratio:
10.0:1
Horsepower SAE Net:
234 hp @ 5500 rpm
Torque SAE Net:
267 lb-ft @ 3500 rpm
Fuel Delivery:
Bosch L-Jetronic Fuel Injection (CIS-Jetronic)
Fuel Type:
Unleaded Premium Gasoline (91 Octane minimum recommended)
Ignition System:
Electronic Ignition with Knock Sensor
Engine Control Unit Model:
Bosch Motronic ML-1.3 (or similar early Motronic variant)
Cooling Type:
Water-Cooled
Transmission Type:
4-Speed Automatic Transaxle (optional: 5-speed manual transaxle)
Manual Transmission Type:
5-Speed Manual Transaxle (WLS - Werkstuning Leightbau Sport)
Transaxle Layout:
Rear-mounted transaxle (transmission and differential combined) for optimal weight distribution.
Automatic Transmission Fluid:
Porsche ATF-Z (or equivalent Dexron II/III specification)
Manual Transmission Fluid:
GL-4 Hypoid Gear Oil (e.g., Mobilube HD 75W-90 or equivalent)
NHTSA Ratings:
Not extensively tested by NHTSA under modern protocols. Early Porsche models were designed to robust European safety standards.
Braking System:
Four-wheel internally vented disc brakes, ABS (Anti-lock Braking System) standard on 1984 USA models.
Suspension:
Independent front and rear suspension with transverse leaf springs and longitudinal control arms. Self-leveling rear suspension.
Occupant Protection:
Three-point inertia-reel seatbelts, reinforced passenger cell, energy-absorbing steering column.
Audio System:
Original factory AM/FM stereo with cassette player, often branded like Blaupunkt or Becker. Amplified system with multiple speakers.
ABS:
Anti-lock Braking System (ABS) was a significant technological feature for its era.
Diagnostics Port:
Limited integrated diagnostic capabilities compared to modern vehicles. Relies on component-level testing guided by service manuals.
Oil Change Interval:
Every 5,000 - 7,500 miles or 12 months, whichever comes first.
Major Service Interval:
Timing belt replacement every 30,000 - 50,000 miles or 4-5 years (critical for V8 engine).
Engine Oil Type:
SAE 20W-50 Synthetic or Semi-Synthetic Engine Oil meeting Porsche A40 specification (or equivalent API SH/SJ/SL).
Engine Oil Capacity:
Approx. 8.5 Liters (9 US Quarts) with filter change.
Coolant Type:
Ethylene Glycol based coolant with corrosion inhibitors (typically a 50/50 mix with distilled water).
Brake Fluid Type:
DOT 4 brake fluid.
Electrical Gremlins:
Degrading wiring insulation (especially injector harness), failing relays, aged vacuum lines, fuel pump failure, dashboard warning light issues.
Mechanical Wear Items:
Timing belt tensioners, water pump, valve stem seals, rear main crankshaft seal, clutch (manual), driveshaft flex joints (guibos).
Fuel Delivery Issues:
Clogged fuel injectors, weak fuel pump, faulty fuel pressure regulator, vacuum leaks in fuel lines.
Cooling System:
Regular flushing and refilling of coolant, checking for leaks, ensuring fan operation.
Porsche Legacy:
Renowned for engineering excellence, motorsport success, and high-performance sports cars dating back to the 1940s.
928 Genesis:
Introduced in 1977 as a successor to the 911, featuring a front-engine, water-cooled V8 layout, a radical departure for Porsche.
928 Generation Changes:
The 1984 model represents the 'S' variant, featuring engine upgrades and revised styling compared to earlier models.
Production Years:
1977-1995
Manufacturing Location:
Stuttgart, Germany
Import Car Of The Year:
Motor Trend Import Car of the Year for 1978.
General Reputation:
Acclaimed for its engineering, comfort, and performance as a GT, though some criticized its departure from traditional Porsche design.
Manufacturer Designation:
Porsche 'Weltmeister' (World Champion) for automotive engineering and quality.
