TableEngine AssemblyEngine Inspection3-2 Note:
Check the belt distortion at the specified point (see Figure 1-1).
When mounting a new belt, set the tensioning force to specified value.
After the belt has been operated more than 5 minutes, check and ensure the distortion not exceeding specified
value. (2) Make sure that the coolant level is above the neck of the radiator.
(3) Put the radiator cover in place, pressurize to 2.0Mpa, and keep the pressure for 1minute unless the coolant
leaks. (Mount a tester on the radiator cover, start the engine, and then shut down under a pressure 2.0Mpa).
(4) Check whether the coolant quantity in the dilatation can is between the mark "Low" and "Full".
(5) Check whether the radiator cover is clean; test whether the opening pressure of the main valve is 107.8KPa
with a radiator cover tester. The minimum opening pressure is 58.5KPa.
6. Check the battery.
(1) The terminal voltage of the battery is 12.5-12.9V at 20°C, and charge when the voltage value is less than
the specified value. Check whether the fusible cutout and the fuse are loose, corrosive or on.
7. Check the air filter.
(1) Whether the cover, the case or the element of the filter is distorted, corroded or damaged.
(2) Whether the air hose is damaged.
(3) Whether the air chamber is distorted or damaged.
(4) Whether the air filter element is blocked, polluted or damaged. If the filter element is blocked slightly,
remove the dirt by blowing the element from above.
(5) Whether there is any pollutant or dirt on the air filter support.
8. Check the spark plug.
(1) Spark generation.
a. Disconnect the coupling of the injector.
b. Remove the spark plug from the secondary wire.
c. Remove the spark plug.
d. Connect the spark plug to the secondary wire.
e. Ground the spark plug.
f. Start the engine, and check whether spark is generated.
Prompt: The starting time is not more than 1-2s.
(2) Clean the spark plug: The air pressure is not greater than 588kp and the time is not more than 20s.
(3) Check whether the thread and the insulator of the spark plug are damaged. Replace if necessary.
(4) Check the electrode gap of the spark plug: 0.8±0.1mm for MR479Q and MR479QA; 1±0.05mm for
MR481QA.
9. Check the driving belt.
Belt distortion (see Table 1):
Belt pressure: 98NMeasure belt loosenessCompressor
Crank Power steering
pumpWater
pump
Alternator2 1
3Figure 1-1New belt mm Used belt mm
Generator drive belt 7~9 11.5-13.5
Power steering belt 5~6 6~8
Air conditioner belt 6.5~7 8~9 -
Figure 1-2
Figure 1-3Engine AssemblyEngine Inspection3-3 After the belt is re-mounted and operates more than 5 minutes, check the distortion based on old belt
distortion.
Check the tensioning force and the distortion of the V-belt after the crankshaft of the engine has rotated 2
turns.
10. Check the ignition timing (see Figure 1-2).
(1) Start the engine for warming up.
(2) When using the portable tester:
Connect the portable tester to the fault diagnosis socket
(DLC3).
Ignition timing:
before the top dead center when idling.
Prompt:
Please refer to the operating manual of the portable tester for
detail.
(3) When not using the portable tester:
a.Short the terminals 13(TC) and 4(CG) of the fault diagnosis socket(DLC3) with special service tool(SST).
Attention:
Make sure to connect correctly, or else the engine can be damaged.
Switch off all the electric systems.
Check when the cooling fan motor is disconnected.
b.Check the ignition timing with a timing light.
Ignition timing: 10°±20' before the top dead center when idling.
Note:
(a) Check the ignition timing, and the transmission should be set to the neutral position.
(b) Keep the engine speed at 1,000-1,300r/min for 5s and check when idling.
(c) Remove the special tool on the fault diagnosis socket.
(d) When the engine speed rises, the advance angle of ignition timing will increase.
(e) Remove the timing light.
11. Check the engine idle (see Figure 1-3).
(1) The engine warms up.
(2) When using the portable tester: Connect the portable tester to the fault diagnosis socket (DLC3).
Tip: Please refer to the operating manual of the portable tester for
detail.
(3) When not using the portable tester:
Connect the test pen of the tachometer to the terminal 9(TAC) of
the fault diagnosis socket (DLC3) with special tool (SST). (see
Figure 1-3).
(4) Check the idling speed: 800±50r/min.
Attention:
Check idle when the cooling fan motor is disconnected.
Switch off all the electric accessories and air conditioners.Tachometer
Battery10°±20' -
12. Check the compressing pressure (see Figure 1-4).
(1) Warm up and switch off the engine.
(2) Remove the secondary wire.
(3) Remove the spark plug.
(4) Check the compressing pressure in the cylinder.
a.Insert the pressure gauge into the spark plug bore.
b. Throttle widely opens.
c. Rotate the engine crankshaft and measure the compressing
pressure (see Table 2).Figure 1-4Table 2Cylinder compressing pressure (KPa)Pressure difference range of cylinders of this model (KPa)Minimum compressing pressure (KPa)MR479Q MR479QA MR481QA
1250 1320 1360
100
980
Attention:
The electric quantity in the battery should be always enough, and the engine speed should be not less than
250r/min.
Check the compressing pressure in other cylinders in the same way.
Measure as soon as possible.
(5) If the compressing pressure in more than one cylinder is relatively low, fill a bit engine oil to the cylinder
through the spark plug bore, and repeat step a to c to check.
Tip:
If the compressing pressure is increased after the oil is filled, the piston ring or the cylinder may be worn or
damaged.
If the pressure is still low, the valve may be jammed or badly sealed, or the washer may be leaked.
13. Check CO/HC.
(1) Start the engine.
(2) Keep the engine running at a speed of 2500 r/min for about 180s.
(3) During idling, insert the test bar of CO/HC instrument into the exhaust pipe about 40cm depth at least.
(4) Check the concentration of emission of CO/HC at idle speed and at a speed of 2500 r/min respectively.
Tip:
Measure within 3 minutes.
Test the concentration of emission and lambda value of CO/HC at idle speed and at a speed of 2500 r/min
respectively according to GB18352.3-2005 standard.
(5) If the concentration of CO/HC is not up to standard, carry out fault diagnosis by following the steps below.
(1) Check oxygen sensor.
(2) Refer to Table 3 to find possible causes, check and repair.Engine AssemblyEngine Inspection3-4 -
Table 3Section 2 Removal of the Engine Assembly from the Vehicle1. Avoid petrol overflowing (Disconnect from the fuel tank).
2. Remove the front wheel.Figure 1-5Engine AssemblyRemoval of the Engine Assembly from the Vehicle3-5CO
Normal
Low
HighHC
High
High
HighProblems
Bad idle speed
Bad idle speed
(HC reading fluctuates)
Bad idle speed
(Black smoke exhausts)Causes
1. Ignition fault:
Incorrect ignition timing;
Dirt, short circuit, or incorrect spark plug gap.
2. Incorrect valve gap.
3. Suction and exhaust valve leak.
4. Cylinder leaks.
1. Vacuum leaks.
PCV pipe . manifold;
Idle speed control valve;
Brake booster pipeline.
2. Spark lacks since the mixed gas is too thin.
1. Air filter is blocked.
2. PCV valve is blocked.
3. EFI system fails.
ECU fails.
Pressure regulator of fuel oil is out of order.
Water temperature sensor does not work.
Suction pressure/temperature sensor fails.
Injector fails.
The throttle position sensor fails.3. Discharge the coolant completely.
4. Remove the air filter assembly with hose (see Figure 1-5).
(1) Disconnect the joint of the temperature sensor and the wire
plug.
(2) Disconnect the vent duct from the hose of the air filter.
(3) Release the wire clip bolt on the air filter.
(4) Disconnect the hose of the air filter from the throttle body.
(5) Remove 3 bolts and the air filter assemblies.
5. Remove the battery.
6. Remove the fuel pipe sub-assembly.
7. Disconnect the water pipe; disconnect the water outlet pipe of the
heater from the air conditioner pipe.
8. Release the nut and remove the accelerator control cable. -
Chapter 2 Engine MechanicalSection 1 Engine ComponentsComponent ViewFigure 2-1Engine MechanicalEngine Components3-8Upside of radiator support
Engine cover lock assembly
Starter assembly
Output pipe of oil cooler
Input pipe of oil coolerTransmission control cable assembly Fuel oil sub-assembly Accelerator control cable assemble
Water inlet pipe of heater
Water outlet pipe of heaterTransmission control cable assemblySuitable for 1.5L/1.6L(Tight coupling)Suitable for 1.3L/1.5L(Non-tight coupling) Radiator assemblyAir filter assembly with hose
Clutch release assembly
Water inlet pipe of radiator
Water outlet pipe of radiator
Battery -
Chapter 3 Fuel SystemSection 1 Check Fuel System PressureOn-board inspection
1. Check the operation of the fuel pump.
(1) Connect the positive and the negative of the battery to
appropriate connector sockets of the fuel pump (see Figure 3-1).
Attention: Do not start the engine.
If there is pressure present, you will hear that the fuel is flowing.
If there is no pressure present, check the fusible cutout, fuse, EFI
open-circuit relay, fuel pump, ECM (Electronic Control Module) and
circuit joint.
(2) Turn the ignition switch to "OFF".
2. Check the pressure of the fuel.
(1) Check whether the battery voltage is more than 12V.
(2) Disconnect the negative wiring cable from the battery.
(3) Mount a pressure gauge on the fuel input pipe
(see Figure 3-2).
(4) Connect the negative terminal of the battery.
(5) Measure the fuel pressure.
Fuel oil pressure: 265-304kPa
If the pressure is low, check the fuel pipe and connection,
fuel pump, and fuel filter. If the pressure is too high,
replace the regulator.
(6) Start the engine. Measure the fuel pressure at idle speed. The
fuel pressure is 265-304KPa. If the pressure is unsatisfactory, checkFigure 3-1
Figure 3-3 Figure 3-2Fuel SystemCheck Fuel System Pressure3-15the fuel pump, pressure regulator, and injector, and replace if necessary.
(7) After shutting down the engine, check the fuel pressure and
keep the specified pressure for about 5 minutes. The fuel pressure is:
147KPa.
3. The fuel oil pressure regulator (DR) (see Figure 3-3).
Mounting position: On the distributing pipe for fuel.
Faults: Too low or too high fuel pressure, or hard to start.
General causes: Using poor fuel for a long time results in: 1.
strainer blocked; 2. serious leakage caused by particles and impurities.
Other reasons: Man-made mechanical damage, etc.
Maintenance precautions: During maintenance: 1. Never impact the diaphragm element with high pressure
gas; 2. Never clean it with aggressively corrosive liquid; 3. No distortion caused by external force.
Easy measuring method: For the system with oil return, connect a pressure gauge for the fuel on the suction
pipe, start the engine, and run at idle speed. Now, the fuel pressure in the engine should be about 260KPa; pull out
the vacuum pipe of the fuel pressure regulator, and the pressure should be 300KPa approximately.Battery
T conector
Hose
Hose
Fuel Inlet Pipe
Fuel Pipe
Conector -
Section 2 Fuel Pump Inspection1. Fuel pump (1) Check whether the resistance of the fuel pump is 0.2~3.0 ohm¸ at 20°C. If not, replace the fuel pump (see Figure3-4).
(2) Fuel oil pump running:
Switch on the fuel pump with a battery and check. If the operation is unsatisfactory, replace the fuel pump or
wires (see Figure 3-5).
The test should be done within 10s to protect the coil from burning out.
2. Fuel injector assembly
Oil injecting quantity: 40~50cm3/s.
Tolerance of each injector: not more than 10 cm3.
If the fuel injecting quantity is not up to the specification, replace the injector.
Check leakage: Under above conditions, disconnect the wire from the battery, the fuel should not drip one per
minute.Figure 3-4 Figure 3-5BatteryOhm
meterFuel SystemFuel Pump Inspection3-16 -
Figure 5-6
Figure 5-7Above 93°CFigure 5-5Cooling SystemSystem Inspection3-235. Fan
(1) At low temperature (lower than 83°C), check the operation of
the cooling fan.
a. The ignition switch is set to ON.
b. The cooling fan should stop.
c. Disconnect the connector of the water temperature sensor.
(see Figure 5-5)
d.Touch the ground with a wire.
e.Check if the cooling fan rotates.
f. Re-connect the connector of the water temperature sensor.
(2) At high temperature (more than 93°C), check the operation of
the fan (see Figure 5-6).
a. Start the engine, and enable the coolant temperature higher
than 93°C.
b.Check whether the cooling fan rotates.
If not, replace the water temperature switch.
(3) Check the cooling fan (see Figure 5-7).
a. Disconnect the joint of the cooling fan.
b. Connect the battery and the ammeter with the connector.
c. The cooling fan should rotate stably and check the current
readings.
Standard current: 5.7-7.7A.
d. Connect the connector of the cooling fan.disconnectBattery Amper meter -