🏷️ Basic Information

Make:

Porsche

Model:

928

Year:

1980

Market Focus:

USA Model

Chassis Code:

Type 928

Engine Code Variant:

Likely M28.09 for USA models

👋 Introduction

Positioning:

The Porsche 928 was positioned as a grand tourer, blending performance with luxury and advanced technology for its era. This electrical manual caters to the specialized needs of maintaining and repairing its complex systems.

Competition:

Competed with other European luxury GTs like the Jaguar XJ-S, Aston Martin models, and higher-end BMWs and Mercedes-Benz coupes. Its front-engine, rear-drive V8 layout was distinctive.

Vehicle Key Features:

Transaxle layout, 4.5L V8 engine, advanced (for the time) suspension and braking systems, distinctive 'transaxle' design.

Value For Owner:

Empowers owners and independent workshops to accurately diagnose and repair electrical issues, potentially saving significant costs compared to dealership service.

📋 Manual Details

Primary Focus:

Electrical System - Current Flow Diagrams

Additional Coverage:

Troubleshooting electrical problems

Estimated Page Count:

Varies by specific document, but typically 50-150 pages for comprehensive electrical diagrams and troubleshooting.

Type:

Electrical System Manual / Wiring Diagram Manual / Troubleshooting Guide

Language:

English

Format:

Likely printed document or digital PDF (as per typical sales of such manuals)

📖 Manual Coverage

Electrical Systems:

Ignition, fuel injection, lighting (headlights, taillights, interior), instrumentation, power windows, mirrors, wipers, HVAC controls, horn, audio system, starter system, charging system, ECU (Engine Control Unit) wiring.

Troubleshooting Steps:

Step-by-step diagnostic procedures for common electrical faults, identification of fault sources, guidance on using test equipment (multimeter, test lights).

Repair Guidance:

Instructions for repairing or replacing electrical components, wire harness repair, connector diagnosis and repair.

Depth:

Detailed, suitable for basic to intermediate automotive technicians and knowledgeable DIY enthusiasts. Focuses on understanding current flow and diagnosing issues.

📊 Manual Specifications

Digital Format:

If digital, likely searchable PDF with high-resolution diagrams for clarity.

Print Quality:

If printed, expect high-quality paper and clear, crisp printing of diagrams and text.

Binding:

Likely professional binding (e.g., saddle-stitched, perfect bound) for durability in a workshop environment.

Paper Quality:

Durable, often matte finish paper to reduce glare and facilitate use in a workshop.

⚙️ Engine Specifications

Engine Type:

V8, Naturally Aspirated

Displacement:

4.5 Liters (4474 cc)

Bore X Stroke:

94.0 mm x 80.0 mm (approx.)

Horsepower:

219 hp @ 5500 rpm (USA Spec)

Torque:

245 lb-ft @ 3600 rpm (USA Spec)

Fuel Delivery:

Bosch K-Jetronic (CIS - Continuous Injection System)

Fuel Type:

Unleaded Premium Gasoline

ECU Type:

Early electronic engine control for fuel injection and ignition timing.

🔧 Transmission

Transmission Type:

4-Speed Automatic (Standard for USA models)

Transmission Type:

5-Speed Manual (Rare in USA market, primarily European).

Layout:

Rear-mounted transaxle design (engine front, transmission rear) for optimal weight distribution.

Automatic Transmission Fluid:

Dexron III or equivalent (Consult specific Porsche documentation for exact spec).

📐 Dimensions

Length:

4655 mm (approx.)

Width:

1785 mm (approx.)

Height:

1280 mm (approx.)

Curb Weight:

1550 kg (approx.)

Wheelbase:

2434 mm (approx.)

🛡️ Safety Features

Crash Test Data:

As a 1980 model, official modern crash test ratings (e.g., NHTSA, IIHS) are not directly comparable. However, Porsche vehicles of this era were built with robust structures.

Braking System:

Four-wheel Disc Brakes, Power Assisted

Suspension:

Independent front and rear suspension with transverse leaf springs (front) and coil springs (rear), designed for excellent handling.

Seat Belts:

Three-point inertia-reel seat belts

Body Construction:

High-strength steel unibody construction.

💡 Technology Features

Audio System:

Typically featured an AM/FM radio with cassette player, often with amplifier(s) and multiple speakers. Electrical diagrams are essential for troubleshooting these systems.

ABS:

ABS (Anti-lock Braking System) was optional on some later models, but typically not standard on the 1980 USA model. If equipped, its electrical components would be covered.

Diagnostic Ports:

No OBD-I or OBD-II ports. Diagnostics relied on analog gauges, indicator lights, and direct electrical system analysis using the provided diagrams.

🔧 Maintenance

Oil Change Interval:

Typically every 5,000-7,500 miles or annually (consult owner's manual for precise interval).

Major Service:

Timing belt replacement is crucial, typically every 60,000 miles or 5 years. This manual's electrical focus is critical for sensors and control systems related to engine timing.

Engine Oil Type:

SAE 20W-50 or 10W-40 (API SF or SG rated) is commonly recommended for air-cooled engines, but for the 928's water-cooled V8, consult specific manual. Modern multi-grade synthetic oils are often preferred for longevity.

Coolant Type:

Ethylene Glycol-based coolant (e.g., G11 standard) with appropriate corrosion inhibitors. Capacity ~10 liters.

Brake Fluid:

DOT 3 or DOT 4.

Electrical Common Issues:

Aging wiring insulation (especially in engine bay), failing relays and switches, issues with the fuel injection control unit, degradation of vacuum lines affecting engine performance, problems with power accessory motors (windows, seats).

Mechanical Common Issues:

Timing belt failure (critical), front suspension arm wear (sometimes referred to as the 'tear drop' bushings), fuel pump issues, transaxle seal leaks.

Importance Of Electrical Checks:

Regular checks of wiring, grounds, and connections are vital for reliable operation of the fuel injection, ignition, and other critical electronic systems.

📚 Vehicle History

Brand Legacy:

Porsche is renowned for its sports car heritage, focusing on performance, engineering excellence, and driver engagement.

928 Development:

Developed as a potential successor to the iconic 911, aiming for a more comfortable, powerful, and modern GT experience. It was Porsche's first front-engined V8 production car.

1980 Updates:

The 1980 model year saw minor refinements over the initial launch, maintaining the core V8 engine and transaxle design. Continuous evolution throughout its production run (1977-1995).

Manufacturing Location:

Stuttgart, Germany

🏆 Awards & Recognition

European Car Of The Year:

The Porsche 928 was awarded European Car of the Year in 1978, highlighting its innovative design and engineering.

Modern Classic Status:

Highly regarded as a modern classic and a significant milestone in Porsche's history.