Chery A21 2005, Service Manual, Page: 343 / 475

CHERY
·
A21 SERVICE MANUAL ENGINE EFI SYSTEM
20
3.7 ELECTRIC FUEL PUMP
1)Exterior drawing and pin
The electric fuel pump has two pins connecting
to pump relay. There are
“
+
”
and
“
-
”
showing
anode and cathode on the pump housing near to
pins.
2)Installation position: inside fuel tank
3)Purpose: Deliver the fuel to engine fuel
supplying pipe at certain flow and fuel pressure
and keep the stable fuel pressure (realized by
fuel pressure regulator)
4)Working principle
The electric fuel pump is made up of DC
electromotor, vane pump and end cover (it
’
s an
integration of check valve, relief valve and an
anti electromagnetic interference element).
Pump and electromotor are coaxial assembly
and within the same casing. The pump and
electromotor are full of gasoline for coolant and
greasing inside of the casing. The accumulator
provide power to electric fuel pump via fuel
pump relay, and the relay switches on electric
fuel pump only when engine starting and
running. When the engine stops for some reason,
the pump will stop to run by itself.
5)Working voltage: 8
—
14V
Working temperature: -30--70
℃
System pressure: 300KPa
6)Malfunction and diagnosis method
l
Malfunction: big running noise, badness
acceleration, can not start (difficult to start)
etc..
l
Reason: use of low quality fuel and cause 1,
colloid became insulation layer; 2, fuel
pump bushing and armature come to
together; 3, components of fuel level sensor
eroded.
l
Service notice: 1, the electric fuel pump can
Chart 3-12 Exterior Drawing of Electric
Fuel Pump
Chart 3-10 Exterior Drawing Of Phase
Sensor
Power Supply
Electric Fuel Pump
Fuel Pump Relay
Connect
To Main
Relay
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