misfired

Misfired is an adjective used to describe an action or event that failed to ignite or start as intended, or a device or mechanism that did not operate correctly. The term combines mis- with fire and is used across mechanical and technical contexts to denote a failure of ignition or initiation.

In firearms, a misfire refers to a cartridge that fails to ignite after the firing mechanism is actuated. Causes include a faulty primer, damp powder, a damaged or improperly seated cartridge, or a malfunctioning action. Safety protocols emphasize treating a misfired round as potentially dangerous: keep the weapon pointed in a safe direction, wait a moment, and follow proper unloading procedures and inspection if the issue recurs.

In internal combustion engines, a misfire occurs when one or more cylinders fail to ignite the air–fuel mixture at the proper time. Symptoms include rough idle, reduced power, and higher emissions. Common causes are worn or fouled spark plugs, defective ignition coils, clogged fuel injectors, insufficient fuel pressure, vacuum leaks, or timing problems. Diagnostics may involve check engine codes, spark and compression tests, and fuel system evaluations. Remedies range from replacing spark plugs or ignition coils to repairing fuel delivery components, fixing vacuum leaks, or correcting timing.

Misfiring can also occur in other propulsion or ignition systems, such as artillery or rocket propulsion, where a propellant charge fails to ignite as planned. In all contexts, misfires warrant careful handling, assessment of root causes, and appropriate corrective action to restore reliable operation.