What Is a Misfiring Engine?

At its core, an engine misfire occurs when the combustion reaction doesn't work correctly, and your cylinder remains unfired. Misfires can occur both upon engine startup and even in the middle of engine idling. When a misfire happens, your engine might momentarily stumble, and it may even lose speed (RPMs).

What does an engine misfire feel like?

Misfires can happen when a vehicle is under load while accelerating. This causes slow or sluggish acceleration and your vehicle may have trouble getting up to speed. You might feel a jerking motion when pressing down on the throttle. The most common cause of an engine misfire when accelerating is worn-out spark plugs.

What does it mean when an engine is misfiring?

An engine misfire is when one or more cylinders doesn't produce power, and there are several possible causes, from a fouled spark plug to a clogged fuel injector or faulty oxygen sensor.