The injector is an electromechanical device for precise dosing injection evaporated and filtered gas in vehicles with gasoline engines. When choosing the injector should be noted in fact familiar with its characteristics. Important here are the minimum linear shutter, injector flow rate at maximum opening, the coil resistance (power consumption), the possibility of installing a data type of vehicle in terms of available space and the accuracy of their location. Most injectors available and the most popular on the market VALTEK, RAIL, requires prior testing or preparation prior to installation, it is a check piston stroke, which is of crucial importance for uniform gas dosage for each cylinder.