Use a spark plug socket to remove the spark plugs in your engine and look them over to diagnose problems that may exist.  Remove each plug and inspect them for specific types of damage that may indicate what’s keeping the engine from starting.  Tan or grey metal plugs are in good working order. Black or burnt plugs indicate that there is too much fuel going into the engine. Blisters or boiling on the plug indicates that the engine was severely overheated. If the spark plugs appear to be fouled out, you will need to address the issue that caused them to foul in order to make the engine run properly.  Once done, replace the damaged spark plugs with new ones.  Make sure to gap new spark plugs properly for your application. You can find the appropriate gap to put into the plug in the service manual for your vehicle. Ensure each of the spark plug wires is securely fastened to the spark plug and to the ignition coil.  You can also use an ohm meter to conduct a spark plug resistance test to ensure the plug wires are transmitting sufficient electricity to the spark plugs to ignite the air and fuel mixture within the engine.  Look for signs of damage such as fraying or cracks in the spark plug wires. Replace any damaged spark plug wires even if they are not what’s keeping the engine from starting. Although unlikely, if all of your ignition coils fail to function it will prevent the engine from starting.  Test your ignition coils by removing a spark plug and connecting it again to its plug wire.  Touch the metal from the plug to a piece of metal in the engine bay and have a friend turn the key in the ignition.  If the coil is functioning properly, you will see a blue spark come from the plug. Test each ignition coil in your engine.
تفقد شمعات الإشعال بحثًا عن دلالات تضرر. استبدل شمعات الإشعال عند الحاجة لذلك. تفقّد كابلات الشمعات. اختبر ملفات الإشعال.