Engine Misfire: Causes, Signs, and How to Fix It

When your engine misfire, a condition where one or more cylinders fail to ignite fuel properly. Also known as cylinder misfire, it’s not just a rough idle—it’s your car telling you something’s wrong inside the combustion chamber. You might feel it as a stutter when accelerating, hear a popping sound from the exhaust, or notice your check engine light flash. Ignoring it doesn’t make it go away. It just makes repairs more expensive.

Engine misfire doesn’t happen for no reason. It’s usually tied to one of three systems: spark plugs, the components that ignite the air-fuel mixture in each cylinder, the fuel system, which delivers the right amount of fuel at the right time, or the ignition system, including coils and wires that deliver the spark. A worn spark plug—something we talk about in detail in our guide on spark plug lifespan—is the most common culprit. But a failing fuel pump, dirty fuel injectors, or even a bad clutch (yes, really) can also trigger misfires by messing with engine timing or fuel flow.

Here’s what you can check yourself: Does the engine shake at idle? Does it hesitate when you press the gas? Is there a strong smell of unburned fuel? These aren’t just annoyances—they’re clues. A misfire can damage your catalytic converter, which costs hundreds to replace. It can also lower your fuel economy by 15% or more. You don’t need a diagnostic tool to spot the early signs. Listen. Feel. Smell. Then act.

The posts below cover real-world cases of engine misfire linked to other parts you might not think are connected—like a failing fuel pump, worn spark plugs, or even clutch problems that throw off timing. You’ll find clear signs to watch for, cost estimates for repairs, and what you can fix yourself versus when to call a pro. No fluff. No theory. Just what actually breaks, why it breaks, and how to fix it before it breaks worse.