It’s not easy to diagnose a fuel injector problem, as the symptoms it causes are very much similar to a bad spark plug or ignition coil. Common symptoms of injector errors are, engine runs very rough, the cylinder is not firing and the engine not making peak power. There are three common issues that a fuel injector usually runs into, which is, becoming clogged or leakage. If the injectors are clogged some liquid injector cleaners may help reduce the build up. The most effective way to clean them is removal and usage of proper chemicals and equipment.