- engine misfires;
- loud noise when the engine is running in one or more cylinders;
- engine overheating;
- loss of power;
- black color of exhaust gases;
- increased fuel consumption;
- deep blue color of exhaust gases when starting a cold engine.
A faulty injector can be identified by disconnecting the fuel supply lines one by one while the engine is running at high speed. If the engine sound does not change when the fuel line is disconnected from a particular injector, the injector is faulty.