Why “Top”? Because Vialle’s Liquid Phase Injection (LPI) isn’t your grandfather’s vapor carburetion. It’s a high-pressure, cryogenic ballet happening inside your intake ports.
It sounds like you're looking for a related to the LPI Vialle system—likely for LPG (autogas) or alternative fuel conversions—specifically the "Top" model or series. lpi vialle technical manual top
A standard Vialle LPi installation consists of several critical hardware units integrated into the vehicle's fuel and electrical systems: Why “Top”
Reliable operation requires periodic checks of the pressurized components and electrical connections. Scheduled Maintenance : Specialized components like the LPG sequential regulator lpi vialle technical manual top