After b50 maintenance, the car still won't catch fire when it is cold. Maintenance items: replace spark plugs and cylinder lines, and clean solar terms.

Generally speaking, to ensure the normal use of cars and increase their service life, maintenance is needed:

1. Whether the protective coating on the underbody is damaged.

2. Replace the fuel filter and spark plug.

3. Check the V-ribbed belt and replace it if necessary.

4. Whether the engine timing belt is cracked or damaged, and replace it if necessary.

5. Whether the engine oil pan bolts are loose, and tighten them according to the specified torque when necessary.

6. Whether the brake hose is aging or damaged, whether the brake hard pipe is damaged or corroded, and whether the joint leaks oil.

7. Whether the joint of the fuel system is aging or damaged, and whether it is loose or worn.

8. Check whether the rubber parts and rubber bearings connected between the front and rear frames and the car body are damaged or permanently deformed.

9. Whether the hinges of the left and right control arms and the rear axle are damaged or failed.

In addition, the brake fluid must be changed every two years or 50,000 kilometers, and the brake alarm system and brake booster must be checked. For manual transmission vehicles, change the transmission gear oil every 12 months or 50 00 kilometers. Vehicles equipped with automatic transmission should always check the transmission gear oil and change the gear oil every 30 000 kilometers.

These maintenance items are for reference only. Please refer to the vehicle maintenance manual for specific models.