Gas (Petrol) Service
Fuel System Types
Before beginning a service determine if the vehicle being serviced has a return or returnless fuel system.
Return Fuel System
A return system has 2 fuel lines, one from the fuel tank to the fuel rail and one returning to the fuel tank.
A regulator maintains the correct fuel rail pressure by returning any excess fuel back to the tank. These
systems work by having a pressure regulator at the end of the fuel rail that returns any excess flow back to
the tank. The regulator has a connection to the intake manifold to allow for a slight boost of pressure as the
throttle is opened. It is never recommended to deadhead a pump on a vehicle with a return fuel system.
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