Pressure regulator and fuel manifold

PRESSURE REGULATOR AND FUEL MANIFOLD

The mechanical, membrane type pressure regulator is fitted to the fuel manifold and is not adjustable. The one-piece fuel manifold supports both injectors and pressure regulator.

The pressure regulator consists of a metal case that houses a mobile unit and membrane (4) loaded by spring (5). Once a pre-established force made up of the vacuum present on the opposite side of the membrane and load of spring (5) has been overcome, fuel forced out by the pump brings about opening of valve (7) that permits excess fuel to flow back through pipe (2) to the tank.

The spring housing chamber communicates with the intake duct of engine (6) (vacuum signal). This arrangement maintains a constant difference between fuel pressure and intake duct pressure under all engine service conditions.

Pressure regulator setting: 3±0.2 bar
With engine idling 2.5±0.2 bar (vacuum about 0.5 bar).

1. Fitting connected to fuel inlet line
2. Fitting connected to fuel return line
3. Injector and fuel manifold support
4. Membrane with reflux valve
5. Regulating spring
6. Pipe connected to vacuum in intake manifold
7. Reflux valve
8. Metal case