MotorVac CarbonClean1000 - Manual (Page 10)

    2012 MotorVac, Inc.
9
Service Procedure
Fuel System Types
Before beginning an exchange determine if the vehicle being serviced has a return or
returnless fuel system.
Return Systems
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.
NOTE: The fuel pump must be disabled for return fuel systems as dead heading
the pump can cause damage to the pump or fuel system.