Target Audience:
Porsche 928 owners, independent workshops, and automotive technicians specializing in Porsches.
Value Proposition:
Empowers owners and technicians to perform complex electrical diagnostics and repairs, reducing reliance on expensive dealership services.
Uniqueness:
Directly from factory/OEM sources, ensuring accuracy and completeness for the specific model year and variant.
Usability:
Designed for practical application, with illustrations and diagrams that are understandable even for those with basic electronic knowledge.
Primary Focus:
Electrical Systems Troubleshooting and Repair
Secondary Coverage:
Component Functionality and Wiring Diagrams
Estimated Page Count:
Detailed, often exceeding 200 pages for comprehensive wiring.
Type:
Wiring Diagram Manual / Electrical Troubleshooting Manual
Engine Management Electronics:
Fuel injection (K-Jetronic), ignition system, ECU functions.
Lighting System:
Headlights (including pop-up mechanism), taillights, interior lighting, fog lamps.
Instrumentation And Gauges:
Speedometer, tachometer, fuel gauge, oil pressure, temperature, warning lights.
Climate Control System:
HVAC blower, actuators, temperature control unit, A/C compressor clutch.
Power Accessories:
Power windows, power seats, power mirrors, central locking, sunroof (if equipped).
Audio System:
Factory radio, amplifier (if equipped), speaker wiring.
ABS System:
Anti-lock Braking System wiring and component connections.
Wiper And Washer System:
Wiper motor, washer pump, controls.
Horn System:
Horn operation, relay, switch.
Trailer Tow Connections:
Wiring for trailer lights and accessories.
Troubleshooting Guides:
Systematic approaches to diagnose electrical faults.
Wiring Diagram Interpretation:
Detailed explanations of schematic symbols and connections.
Component Testing:
Guidance on testing individual electrical components for functionality.
Fuse And Relay Identification:
Location and function of all fuses and relays.
Ground Point Locations:
Identification of all chassis and system ground points.
Connector Pinouts:
Detailed diagrams of connector configurations and pin assignments.
Diagnostic Level:
Advanced diagnostic procedures for complex electrical issues.
Repair Procedures:
Detailed steps for repairing or replacing electrical components and wiring harnesses.
Circuit Analysis:
Understanding of how individual circuits function and interact.
Component Specifications:
Electrical resistance, voltage, and current specifications for key components.
Engine Type:
V8, Naturally Aspirated
Displacement:
4.7 Liters (4664 cc)
Bore X Stroke:
94.0 mm x 84.0 mm
Compression Ratio:
10.0:1
Horsepower:
Approx. 310 PS (228 kW) DIN (European spec, US spec slightly lower)
Torque:
Approx. 430 Nm (317 lb-ft) DIN (European spec)
Fuel Injection:
Bosch K-Jetronic (CIS-E with Lambda control)
Fuel Type:
Unleaded Premium Gasoline (95 RON or higher)
Ignition Type:
Electronic Ignition with Distributor
Transmission Type:
5-Speed Manual Transaxle
Transmission Type:
4-Speed Automatic Transaxle (Tiptronic not yet available)
Transaxle Design:
Rear-mounted transaxle for optimal weight distribution.
Manual Transmission Fluid:
GL-4 SAE 75W-90 Synthetic Gear Oil
Automatic Transmission Fluid:
Dexron III Automatic Transmission Fluid
Length:
4,655 mm (183.3 in)
Width:
1,780 mm (70.1 in)
Height:
1,280 mm (50.4 in)
Wheelbase:
2,433 mm (95.8 in)
Curb Weight Manual:
Approx. 1,580 kg (3,483 lbs)
Curb Weight Automatic:
Approx. 1,620 kg (3,571 lbs)
Cargo Volume:
Rear hatch with limited luggage space; additional space behind rear seats.
Crash Test Data:
Limited public data for this era, but designed with Porsche's inherent safety focus.
ABS:
Standard Anti-lock Braking System (ABS)
Brakes Front:
Ventilated Discs, 304 mm diameter
Brakes Rear:
Discs, 300 mm diameter
Airbags:
Driver's side airbag (standard in 1987)
Seatbelts:
3-point inertia reel seatbelts with pretensioners
Chassis Construction:
Reinforced safety cell, crumple zones
Audio System:
Factory installed premium sound system, often with amplifier and multiple speakers.
Climate Control:
Automatic climate control with temperature and fan speed regulation.
Cruise Control:
Standard electronic cruise control.
Data Communication:
No modern OBD-II or CAN bus communication; troubleshooting relies on analog circuits and specific diagnostic tools of the era.
Oil Change Interval:
Every 10,000 km (6,000 miles) or annually.
Timing Belt Replacement:
Every 60,000 km (37,000 miles) or 4 years.
Brake Fluid Flush:
Every 2 years.
Engine Oil Specification:
API SG/SH, ACEA A2-96, SAE 5W-40 or 10W-40 Synthetic
Coolant Type:
Glysantin G48 (or equivalent) with distilled water (50/50 mix)
Power Steering Fluid:
Pentosin CHF 11S or CHF 202
Electrical Gremlins:
Age-related degradation of wiring insulation, connector corrosion, and relay failure is common. This manual is essential for addressing these.
Fuel System Maintenance:
K-Jetronic system requires precise adjustments and clean components for optimal performance.
Cooling System:
Can be prone to leaks if not properly maintained; proper bleeding is critical.
Manufacturer:
Porsche AG, Stuttgart, Germany
Generation:
Second generation of the 928, evolving from the original 1978 model.
S4 Introduction:
The 'S' model was revised into the 'S4' in 1987, with significant engine and aerodynamic enhancements.
Production Period:
1978–1995 (overall 928 model line)
Manufacturing Location:
Stuttgart, Germany
