1. ### Spark Plug: The spark plug in the number 4 cylinder may be worn out or damaged, preventing it from creating a spark to ignite the fuel mixture. Check the spark plug and replace it if necessary.
2. ### Spark Plug Wire: The spark plug wire for the number 4 cylinder may be damaged or disconnected, preventing the spark plug from receiving power. Check the spark plug wire and replace it if necessary.
3. ### Fuel Injector: The fuel injector for the number 4 cylinder may be clogged or damaged, preventing it from delivering fuel to the cylinder. Check the fuel injector and clean or replace it if necessary.
4. ### Compression: There may be a problem with the compression in the number 4 cylinder, which is necessary for the engine to create power. Check the compression and have the engine repaired if necessary.
5. ### Valves: The valves in the number 4 cylinder may not be opening or closing properly, preventing the fuel mixture from entering or exiting the cylinder. Check the valves and have them adjusted or replaced if necessary.
6. ### Head Gasket: The head gasket between the cylinder head and the engine block may be damaged, allowing coolant to leak into the cylinder and causing it to misfire. Check the head gasket and replace it if necessary.
If you are unable to identify and fix the problem yourself, you should take your vehicle to a qualified mechanic for diagnosis and repair.
