Chery automobile Service Manual page 124

Electrical fuel pump
Function: Supply the fuel from the fuel tank to the
engine at required pressure and flow (vary from
individual system).
Structure and working principle: The electrical fuel
pump is comprised of direct current motor, vane pump
and end cover (integrated with non-return valve, release
valve and anti-electromagnetic interference elements).
The pump and the motor are mounted on the same shaft
and sealed in the same house. The pump and motor are
surrounded by the gasoline for cooling and lubrication.
The battery supplies power to the electrical fuel pump
through the fuel pump relay and the pump relay
switches on the circuit of the electrical fuel pump only
during start-up and operation of the engine. If the
engine stops running due to malfunction, the fuel pump
Electrical fuel pump
will stop operation automatically. The maximum
pressure at exit of the electrical fuel pump is
determined by the release valve within the range of
450-650 kPa. However the pressure of the whole fuel
system fluctuates along with fluctuation of the air
intake manifold pressure. The difference between the
system pressure and the air intake manifold pressure,
which normally is 350kPa, is determined by the fuel
pressure regulator.
Note: The temperature of fuel has a large impact on
performance of the fuel pump. When running under
high temperature for a long time, if the fuel temperature
is higher than a certain temperature, the pressure of the
fuel pump will be decreased rapidly. So please check
carefully whether the performance of the fuel pump
under high temperature is good if the engine fails to hot
start.
Pins: The electrical fuel pump has two pins connecting
to the fuel pump relay. Beside these 2 pins there are
marks of "+" and "-" on the shell of the fuel pump
respectively, which represent the positive and negative
grid.
The 70# pin of ECU controls the fuel pump relay.
Circuit diagram of the electrical fuel
G-15