Engine Misfire causes have to be known to everybody in the sense of a future loss if that misfire continues with its symptoms. Check out also the symptoms for the engine misfire article for details.
Engine misfire can be observed by symptoms but their causes are difficult to find out. Moving engine components failure, electrical failure, Ignition system failure, fuel problems, these are some key causes for the engine misfire.
1 – Ignition System failure
If CI Engines are modulated with misfire then there are problems regarding injectors or fuel related to fuel-air supply. On the other hand, SI Engines generally means petrol engines have this misfire issue because of spark plugs and ignition supply.
Spark plugs have a specific lifespan. After that they should be replaced otherwise their failure can cause this misfire crisis. Spark should be ignited in a combustion chamber to burn the fuel-air charge. If a spark is not there then the stroke is failed to generate power that further results to misfire.
Distributors and ignition coils produce large voltage supply to the spark plugs. If any failure occurs in ignition coils then voltage supply can not be proper that also causes no spark then misfire will be there. The distributor should be well-timed, if it is advanced or retarded then spark produced would be mistimed.
Damaged or worn spark plug wires also cause the interruption in spark. If misfire occurred then check every electrical connection to the spark plug. Also, check the spark plug gap. Corrosion on spark plug, coil, and wires also break that spark and misfire occurs.
2 – Fuel problems
In this type of cause, dirty fuel failed fuel injectors and bad fuel supply are responsible. If you fill a car’s fuel tank with dirty fuel or different grade specified fuel is filled in a tank then the engine can misfire.
Bad or failed fuel injectors if they don’t supply fuel correctly then misfire occurs. Another reason for a misfire is a bad fuel supply system or bad fuel filter (clogged) that also causes misfire due to insufficient or incorrect fuel supply.
3 – Electrical failure
Mass airflow sensor failure, wiring problems, signal problems related to air-fuel injection causes the incorrect fuel injection timing, these are some electrical reasons which result in an engine misfire.
4 – Engine components failure
Damaged and worn out engine body parts are also responsible for engine misfire. They produce leakage or extra gap. The timing belt also affects the correct valve timing. Other moving parts such as piston, piston rod, bearings, valve springs, valve seals, cylinder head, gaskets can also be damaged then misfire or vibration occurs.