CHECKING FUEL INJECTORS

Usually a tech will listen to the injectors with a stethoscope will the vehicle is running

This is a good first thing to try,listening to the clicking of injectors at idle and above idle.One other thing is to mark exhaust outlets as close to the head as u can,with a grease pencil. Run the engine untill you can see most all of the outlets melting the marks away. shut off the motor inspect all outlets,for a cold cylinder,the mark may still be visable on the cylinder that is not making combustion.you may want to try aome injector cleaner in the tank!