What are the reasons for difficulty starting an Audi A6?

[SanAriel]

Audi A6 starting difficulties can be caused by excessive carbon deposits, fuel line blockages or component damage, aging ignition systems, excessively rich air-fuel mixture during startup, damaged water temperature sensors, and fuel injector leaks. Once a vehicle accumulates excessive carbon deposits, it is prone to malfunctions such as idle shaking, difficulty starting, high idle speed, and excessive exhaust emissions, necessitating cleaning. Generally, vehicles should have carbon deposits cleaned every year or every 10,000 kilometers. The Audi A6 is a domestically produced high-end luxury business sedan launched by FAW-Volkswagen. The Audi A6 has a body length, width, and height of 5038mm, 1886mm, and 1475mm respectively, with a wheelbase of 3024mm. The engine model for the Audi A6 2.0T is BPJ, and for the 3.0T model, it is DLZ.