Hisun HS400 Service Manual page 271

Keep a Min distance of 150 mm (around
6") between coil and any VR sensor
device.
Never route the coil C- wire with the same
bundle as the Crank sensor wires. There is
around 200 peak voltage potential
between C- wire and engine ground. This
voltage potential could cause a noise on
sensor cables
Fuel Pump Module
Fuel Pump Module supplies fuel to engine
at system pressure. The Fuel Pump
Module is mounted in the fuel tank and
supplies fuel to engine through hoses.
The Fuel Pump module consists of Fuel
Pump to generate the fuel flow and a
pressure regulator to regulate the fuel
pressure.
Fuel Pump
When power is supplied to the fuel pump,
the motor in the pump assembly rotates
the impeller. Impeller in turn draws the fuel
from strainer and pumps the flow to
generate the system pressure.
Pressure Regulator
Pressure Regulator is a diaphragm type
mechanical device. Fuel flow from filter
enters in the inlet of the pressure
regulator, it then regulates the fuel
pressure at a set pressure by releasing the
excessive fuel flow back into the fuel tank.
Service Procedure:
Before attempting any service on fuel
system, the following cautions should be
followed for personal safety and to avoid
system damage.
Engine Management System
Disconnect negative cable at battery.
DO NOT smoke, and place 'No
SMOKING" sign near work area.
Make sure to have fire extinguisher handy.
Make sure to perform work in well
ventilated area and away from any open
fire/flames.
Wear Safety glasses
To relieve fuel vapor pressure in fuel tank,
remove fuel filler cap fuel filler neck and
then reinstall it.
As fuel lines are at high pressures when
the engine is stopped, loosening or
disconnecting the fuel line will cause a
dangerous spout of fuel. Before loosening/
disconnecting fuel lines, please follow the
"Fuel Pressure Relief Procedure"
described in this section.
A small amount of fuel may drip after the
fuel lines are disconnected. In order to
reduce the risk of personal injury, cover
the pipe/ hose ends with suitable bind with
no rust or contamination.
After servicing, make sure that the fuel
hoses and clamps are connected
according to the hose fitment instructions
given in vehicle instruction manual.
After servicing, please follow the 'Fuel
Leakage Check Procedure' described in
this section.
After servicing make sure to fill at least 3
liters gasoline before pump is primed
(ignition key should be turned on only after
ensuring there is minimum 3 liters of fuel in
the fuel tank).
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