Dobeck Performance TFI Fuel Injection Controller Tuner Gen 2 Techlusion TFIDobeck Performance TFI Fuel Injection Controller Tuner Gen 2 Techlusion TFI The TFI controller functions similarly to a carburetor, allowing for quick fine tuning of your electronic fuel injection system using four adjustment pots and a screwdriver. It is a plug and play unit that monitors signals to the injectors and appends extra pulse width voltage to keep them open longer, effectively adding fuel where needed. Technology: Load based tuning logic