Chery QQ Maintenance Manual 465 EFI System
12. Fuel pressure regulator
Usage: This regulator is not electric component, but it is used to regulate the fuel pressure in
fuel distribution pipe for gasoline engine electronic control system to keep constant value
with the differential of manifold. It controls fuel rate and makes easy for ECU to control fuel
inject pulse width.
Constitute and principle: As shown in the figure, a film made of rubber-fiber separates the
regulator to up and down chambers. The up chamber connects manifold through connector
with hose. There is a spring in the up chamber. The down chamber is filled with the fuel that
flows from the regulator through fuel inlet. The lower part of film gets the fuel pressure in
fuel distribution pipe and the upper part of film gets the pressure of manifold and spring force.
Film deforms to open or close the valve. Since the degree of deforming is very small, the
action force of the spring could be taken as constant. So the open and close of valve is
decided by the difference between the fuel pressure both in the lower chamber and the upper
chamber. If the valve is closed at first, the differential of pressure will increase because of
engine load reducing or fuel pressure increasing, which results lifting the film by fuel pressure
to open the valve. In this way, even the engine working condition is changed, the pressure
differential between fuel distribution pipe and manifold keeps constant. This is the basic
precondition for control fuel fixing quantity. In fact, when fuel flow increases, the differential
increases a little with linearity. When MAP pressure changing, the differential will change
little too.
Fuel request: The regulator can use the fuel according to the standard of “ Non-lead fuel for
vehicle” in GB 17930-1999 and “ The standard for controlling injurant in fuel” in GWKB
1-1999.
Fuel pressure regulator
The section of fuel pressure regulator
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