1. Dead Battery: A car battery naturally discharges over time, especially when left unused. Three years of inactivity will most likely result in a completely drained battery, preventing it from providing sufficient power to start the engine.
2. Fuel System Issues: After a long period of disuse, fuel can become stale, clogged with debris, or evaporate, leading to fuel starvation. Additionally, the fuel pump and fuel filter may have developed issues due to inactivity.
3. Corrosion and Rust: Sitting idle for an extended period can cause corrosion and rust buildup on various electrical connections, terminals, and metal components, impairing electrical continuity and preventing the starter from receiving power.
4. Engine Component Malfunctions: Over time, certain engine components, such as the starter motor, spark plugs, distributor (if applicable), ignition coils, and fuel injectors, may deteriorate or fail due to lack of use and inactivity.
5. Immobilizer Issues: Some BMW models from the 1990s were equipped with an immobilizer system to prevent theft. If the car's immobilizer system has developed a fault or is not properly synchronized with the ignition key, it may prevent the engine from starting.
6. Seized Engine Components: In rare cases, prolonged inactivity can cause engine components to seize due to lack of lubrication. This can prevent the engine from cranking or starting.
7. Rodent Damage: If the car was stored in an area accessible to rodents, they might have chewed on electrical wires, hoses, or other components, causing electrical or mechanical issues that prevent the car from starting.
To address these issues and get the BMW to start, the following steps can be taken:
- Check and replace the battery if necessary.
- Drain the old fuel and refill with fresh fuel. Inspect and clean the fuel lines, fuel filter, and fuel pump if needed.
- Inspect for any visible corrosion or rust on electrical connections and clean or replace affected components.
- Check the starter motor, spark plugs, distributor (if applicable), ignition coils, and fuel injectors for proper functionality and replace any faulty parts.
- Verify the proper functioning of the immobilizer system and ensure that the key is synchronized correctly.
- If the engine is seized, it may require specialized mechanical intervention to free up the components and rebuild or replace the engine as needed.
- Check for any rodent damage to electrical wires, hoses, or other components and repair or replace damaged parts.
It's recommended to seek the assistance of a professional mechanic or BMW specialist to diagnose and address the specific issues preventing the car from starting after such a long period of inactivity.
