Fitments: Mitsubishi Lancer 2009-2013 Mitsubishi Outlander 2008-2013 Product Introduction: A fuel injector is a device for atomizing and injecting fuel into an internal combustion engine. The injector atomizes the fuel and forces it directly into the combustion chamber at the precise point in the combustion cycle. What Are the Signs of a Bad Fuel Injector? Less Engine Power. With at least one cylinder starved of fuel by a bad injector, your engine will rapidly lose power. Misfiring Engine. Rough Idling. Stalling Engine. Thickening Exhaust. Dancing RPM Needle. Check Engine Light. .