Fluctuating engine power, misfiring, fuel smell, not starting and diminished gas mileage can all be signs of bad fuel injectors that may need replacement. Some of these signs can indicate dirty fuel injectors that may be fixed by cleaning, but if the problem persists, permanent engine damage can result.
Fuel injectors that are leaking and in need of replacement are one of the most common problems. Leaking fuel injectors can cause the engine to get inconsistent fuel flow, creating combustion of the fuel and air mix at incorrect intervals and causing rough engine operation or engine flooding. Failing injector valves can stick closed, preventing fuel from reaching the engine, or stick open, which causes the mixture to be too rich.