Chery A15. Manual — part 259

Tips: All the following judgments are based on the normal operation of the vehicle, wire
harness and other system components.

Detached vacuum regulator valve
Polluted adjustor filter
Damaged seal
Damaged pressure regulator (bad modulation or fuel leakage into the vacuum pipe)

Five. Spray nozzle
1. Functions and principles:
The spray nozzle is an electromagnetic switch. Both wire leads of the coil are connected
to the ECM and the power source through the wire harness; the coil, subject to ECM
control, will produce magnetism against the spring, fuel load and vacuum suction of the
manifold to suck the iron core. Then the fuel will go through the valve hole sealing
surface integrated with the iron core and be sprayed in haze into the throttle; when the
power is cut off, the magnetism disappears and the spray nozzle closes.
There is a reliable rubber seal where the injector tip is connected with the fuel rail and
where the injector bottom is connected with the engine intake manifold.
Wiring terminal: 1- +12V

2 – ECM

Second cylinder injector

First cylinder injector

Fourth cylinder injector Third cylinder injector

Fixing: it is fixed onto the air intake manifold through the fuel rail.
2. Component parameters
Working temperature: -40 ℃～130 ℃
Minimum working voltage: 4.5V
Coil resistance: 12.0±0.4Ω
3. Fault diagnosis
Tips: All the following judgments are based on
the normal operation of the vehicle, wire harness
and other system components.
The faults are discovered by the system and
displayed on the diagnostic instrument.
Blocked by foreign matters;
Gelation of fuel after evaporation;
Damaged seal that results in fuel or air leakage;
Detached fittings or damaged wire harness or its own damage;
Incorrect cleaning (long-term electrification) causes leakage in spray nozzle.


Six. Fuel filter and fuel pipeline
1. Functions and principles
Fuel filter
- The function of the fuel filter is to filter the solid foreign matters in the fuel;
- In order to ensure the filtering efficacy and avoid blocked spray nozzle, a special
electronic injection fuel filter shall be adopted for the system;
- The filter casing shall be strong enough, or it will break up subject to fuel pressure.
Fuel pipe
The fuel’s working pressure is about 250 – 350kPa. For the sake of safety, the fuel pipe
must be oil-resistant and feature sufficient safety factor against voltage.
Fixing: the fuel filter is connected in series onto the pipeline between the fuel pump and
fuel rail (to be connected with fuel pipes).

2. Fault diagnosis
Tips: All the following judgments are based on the normal operation of the vehicle, wire
harness and other system components.
Blocked filter and insufficient fuel pressure

Seven. Basic checking of the system
1. Basic structure of the fuel system

油箱

进油

回油

油泵

发动机真空

油压快速检查接头

喷油嘴

油轨

进油压力调节器

碳罐

回油压力调节器

Fuel inlet, return fuel, charcoal canister, fuel pump, fuel tank, return fuel pressure
regulator, pressure gauge tie-in, spray nozzle, fuel rail, inlet fuel pressure regulator,
engine vacuum

2. Fuel pipeline maintenance
Regularly replace gasoline filter;
Clean the fuel tank, fuel pump, fuel pump strainer, pipeline, fuel pressure regulator and
strainer;
Regularly clean the spray nozzle;
Check the sealing of the fuel tank.
3. Check the fuel circuit
Appearance check: check if the fuel circuit suffers any leakage, check for fuel pipe or
fuel tank deformation and if the fuel tank cover can be normally opened and closed.
Check the basic gasoline pressure: run the engine at idle speed, turn on the ignition
switch, straddle the fuel pump and connect the pressure gauge to measure the fuel
pressure which shall be 250 – 300KPA.

Check the maximum fuel pressure: after measuring the basic fuel pressure, tie adhesive
tapes onto a pair of pliers, clamp the fuel return pipe and measure the gasoline pressure
which shall be over 600KPA.
Pressure relief test: after engine flameout, the gasoline pressure shall be reduced by half
within half an hour.
Check the adjusting fuel pressure: run the engine at idle speed and pull out the vacuum
pipe of the inlet fuel adjustor; the gasoline pressure shall increase by around 50KPA.
Check the fuel pump current: turn on the ignition switch, pull out the fuel pump relay
(located near the windscreen wiper motor) and connect an amperemeter to Terminals 30
and 87 of the relay seat; the measured fuel pump current shall be 5-8A.
Clean and test the spray nozzle: clean the spray nozzle (clean for not more than 5
minutes each time), set the spray nozzle angles on the test table to 30 degrees (four spray
nozzles) and align the fuel spray centerline with the spray nozzle axes; the sprayed fuel
shall be evenly distributed with no apparent fuel drops and the fuel flow into each
cylinder shall be normal and the same (as the spray nozzle test table in different
maintenance stations may be different in model, the normal fuel flow shall be tested with
a normal spray nozzle and recorded for reference).