The LPi system works similarly to a petrol-injection system: liquefied fuel is pumped around in the LPi system and offered to the injectors. The system comprises a LPG fuel tank (1) with an integrated pump. The pump increases the pressure in the fuel system and pumps liquefied LPG to the pressure regulator unit. The pressure regulator unit (2) regulates the pressure in the system and has a valve that is opened when the switch from petrol to LPG takes place. The fuel reaches the injectors (3) that are mounted in the inlet manifold. The surplus LPG is returned to the LPG tank along the return lines and pressure regulator. The LPG injectors are driven by the LPG regulation unit (LPE). The signal for the petrol injectors that comes from the original ECU is employed here and translated for the LPG injector. Consequently, all the original signals for the engine management and diagnosis features remain intact.