This comprehensive repair service manual covers Audi 80 and 90 models produced between 1986 and 1991, providing the same detailed information and procedures available to authorized dealer service departments. It serves as a valuable resource for car owners with basic mechanical skills and independent auto service professionals. The manual delves into every aspect of the Audi 80 and 90, including general information, engine service and overhauling, transmission, chassis, body, wiring, fuel system, emission control, induction, mechanical, control system, transmission and differentials, troubleshooting and diagnostics, steering and suspension, brakes, ABS, full specifications and torque settings, and service work. This manual empowers you to diagnose engine fault symptoms, research and evaluate the best repair approaches, test suspected parts using professional techniques, trace and verify wiring diagrams with specific terminal pins connections and expected readings, understand and analyze different engine management systems, and confidently communicate with your mechanic. It also equips you to check the quality of repairs and ensures you are receiving the best possible service. Furthermore, the manual offers practical solutions to common problems such as no-starts, hesitations, and stalling, and provides valuable tips to prevent small issues from escalating.

The Audi 80/90 is a compact executive car produced by German automaker Audi from 1986 to 1991. It constituted the third generation of the Audi 80 model line, and was offered in both saloon (sedan) and estate (wagon) body styles. The 80/90 series represented a significant departure from its predecessors, featuring a new platform and a distinctive, angular design language that was a hallmark of Audi's aesthetic at the time. This generation was also notable for adopting the company's groundbreaking quattro all-wheel drive system as an option, enhancing its handling and performance capabilities. Under the hood, the 80/90 offered a range of petrol and diesel engines, with displacement ranging from 1.3 to 2.3 liters. The car's popularity was further enhanced by its spacious interior, well-appointed features, and reputation for reliability and durability. The 1986-1991 Audi 80/90 series garnered critical acclaim and commercial success, cementing Audi's position as a leading manufacturer of premium, technologically advanced vehicles. The 80/90 generation offered a compelling combination of comfort, performance, and practicality, making it a popular choice for discerning drivers in Europe and beyond. However, the arrival of the fourth-generation Audi 80 model in 1991 marked the end of the 80/90 designation, with the succeeding generations simply carrying the Audi 80 moniker. Despite its discontinuation, the Audi 80/90 remains a significant chapter in the brand's history, showcasing the evolution of German engineering and design excellence in the 1980s.