This comprehensive 1991 Audi 80 90 [8A, 8A2] Service and Repair Manual provides detailed instructions and illustrations to help you completely service and repair your vehicle. It includes all models and covers every repair from A to Z, making it the ultimate resource for both professional mechanics and DIY enthusiasts.

The manual is packed with step-by-step instructions, diagrams, wiring schematics, and specifications. You'll find everything you need to diagnose and repair your Audi 80 or 90, including:

* **Maintenance:** Routine maintenance schedules, fluid capacities, and recommended parts.
* **Engine:** Detailed information on engine operation, troubleshooting, rebuild procedures, and component replacement.
* **Control System:** Comprehensive coverage of the engine control system, including sensors, actuators, and diagnostics.
* **Mechanical:** In-depth explanations of all mechanical components, such as the transmission, suspension, brakes, and steering.
* **Fuel Service Specifications:** Specific details on fuel systems, including injection, delivery, and emissions control.
* **Emission Control:** Guidance on diagnosing and repairing emission control systems, including catalytic converters and sensors.
* **Intake Exhaust Cooling:** Detailed information on cooling systems, including radiators, thermostats, and fans.
* **Lube:** Recommendations on lubricants, fluids, and filter replacement.
* **Ignition Starting Charging:** Thorough coverage of the ignition, starting, and charging systems, including troubleshooting and repair.
* **Auto Transmission Clutch:** Comprehensive guide to automatic transmissions, including troubleshooting, repair, and rebuild procedures.
* **Manual Transmission:** Detailed instructions on manual transmissions, including troubleshooting, repair, and component replacement.
* **Transfer Propeller Shaft:** Information on transfer cases, propeller shafts, and related components.
* **Drive Shaft:** Guidance on drive shafts, axles, and related components.
* **Differential:** Comprehensive coverage of differentials, including troubleshooting, repair, and rebuild procedures.
* **Axle Suspension:** Detailed information on suspension components, including shocks, struts, springs, and control arms.
* **Tire & Wheel:** Instructions on tire and wheel maintenance, including repair and replacement.
* **Brake Control:** Comprehensive guide to brake control systems, including ABS and other electronic systems.
* **Brake:** Detailed information on brakes, including calipers, rotors, pads, and drums.
* **Parking Brake:** Instructions on parking brake operation, adjustment, and repair.
* **Steering Column:** Comprehensive coverage of steering columns, including troubleshooting, repair, and component replacement.
* **Power Steering:** Detailed information on power steering systems, including pumps, hoses, and racks.
* **Air Condition:** Guidance on air conditioning systems, including refrigerant charging, component repair, and troubleshooting.
* **Suppl Restraint System:** Information on supplemental restraint systems, including airbags and seatbelts.
* **Seat Belt:** Detailed instructions on seatbelt operation, repair, and replacement.
* **Engine Immobilizer:** Troubleshooting and repair guide for engine immobilizer systems.
* **Cruise Control:** Comprehensive coverage of cruise control systems, including troubleshooting, repair, and component replacement.
* **Wiper & Washer:** Instructions on wiper and washer systems, including motor replacement, blade adjustment, and fluid replenishment.
* **Door Lock:** Detailed information on door lock systems, including troubleshooting, repair, and component replacement.
* **Meter Audio/Visual:** Guidance on instrument panels, gauges, and warning lights.
* **Horn:** Instructions on horn operation, troubleshooting, and repair.
* **Windshield/Glass Mirror:** Information on windshield and mirror replacement and repair.
* **Instrument Panel:** Comprehensive guide to instrument panel components, including lighting, switches, and controls.
* **Seat:** Detailed information on seat mechanisms, adjustment, and repair.
* **Engine Hood/ Door:** Instructions on hood and door operation, latch replacement, and repair.
* **Exterior & Interior:** Detailed coverage of exterior and interior components, including trim, body panels, and upholstery.
* **Electrical:** Comprehensive guide to electrical systems, including wiring diagrams, troubleshooting, and repair.
* **Multiplex/ Can Communication:** Information on multiplex and CAN bus communication systems.

This manual is an invaluable resource for anyone who wants to understand and repair their Audi 80 or 90. With its detailed information and easy-to-follow instructions, you can save time and money by performing repairs yourself.

The 1991 Audi 80 and 90, designated as the 8A model internally, represent a significant evolution for the German automaker. These compact executive cars marked a departure from the previous generation, boasting a more modern design, refined engines, and an enhanced level of comfort and safety features. The 8A platform, a departure from the previous B2 platform, featured a more rigid body structure, designed to improve occupant safety and handling. Engine options ranged from fuel-efficient four-cylinder units to powerful six-cylinder variants, offering a choice between practicality and performance. Inside, the cabin was characterized by a well-appointed interior with high-quality materials and a focus on ergonomics. Features like power windows, central locking, and a comfortable seating arrangement contributed to a refined and enjoyable driving experience.

Beyond its pleasing aesthetics and comfort, the 1991 Audi 80 and 90 impressed with their technological advancements. The quattro all-wheel-drive system, available on certain models, offered exceptional traction and handling, solidifying the Audis' reputation for performance and safety. The introduction of ABS (Anti-lock Braking System) and airbags further enhanced driver and passenger safety. The 1991 80 and 90 were pioneering models in this segment, offering a combination of German engineering, sleek styling, and advanced features that appealed to discerning drivers. These qualities, along with their durability and reliability, have solidified the 80 and 90 as highly sought-after classics, representing a significant chapter in Audi's history of building performance and luxury cars. While the 1991 model year marks the beginning of the 8A generation, these cars continued to be produced and refined throughout the 1990s, evolving through various facelifts and engine updates. The 8A platform laid the groundwork for future Audi models, shaping the brand's identity and establishing its reputation for innovation and premium quality.