JAC S2. Engine. Instruction — part 12

Engine ignition system

Engine ignition system 154

14. Only use the genuine fuel system parts provided by JAC.

(V) Special tool

SN

Tool

Diagram

Description

1

Fuel pressure gauge

To measure fuel pressure

2

Lock nut fixing plate

Dismount the locknut of fuel pump

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II. Failure diagnosis

(I) Diagnosis analysis table

SN Failure phenomenon

Failure cause analysis

Solution

1

Fuel supply system failure

Insufficient fuel supply by

pump

Repair or replace

Fuel tube and filter

congestion

Clean

2

Insufficient power during

running

Improper adjustment of

acceleration pedal and throttle

valve

1. Check if the throttle, ignition

plug and cylinder head gasket

have leakage

The compressing pressure of

cylinder deminution

2. Cylinder grinded

Insufficient supply of fuel

Adjust or repair

Insufficient air intake

Check the air intake system

Exhaust congestion

Check the exhaust system and

clear the carbon deposit

Improper ignition plug

clearance or ignition plug

damaged

Adjust or repair

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(II) Diagnosis procedures table

The fuel pump doesn’t work

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III. Release the fuel system pressure

(I) Release the fuel system pressure
Attention: After releasing the fuel system pressure, please use the towel to wrap the joints when detaching it
in case of the surplus fuel overflew.

1. Release the fuel system pressure

1) Turn the ignition switch to OFF gear and detach the cathode wire of battery.

2) Dismantle the relay of fuel pump.

Attention: It may appear the failure code when dismantling the relay of fuel pump, please use the
diagnosis device to clear the code after releasing the fuel system pressure.

3) Connect the cathode wire of battery.

4) Start up engine and keep it at idling state, turn the ignition switch to OFF gear when the engine
is OFF automatically.

5) Disconnect the cathode wire of battery then install the relay of fuel pump.

6) Connect the cathode wire of battery.

7) Use the diagnosis device to clear the failure code relative with the relay of fuel pump (if
necessary).

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IV. Fuel tank assy

(I) Disassembly

1. Open the engine hood
2. Release the fuel system pressure
3. Disconnect the cathode wire of battery.
4. Dismantle the rear seats cushion assy
5. Dismantle the fuel tank assy
1) Pry up the access cap of fuel tank by the slot screwdriver.

2) Disconnect the wires connector on fuel pump

3) Loosen the clamp of fuel filling tube and fuel
tank then pull out the filling tube.

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4) Disconnect the fuel tank tube with the tube installed in fender.

5) Screw off the fixed bolt of the
front and rear strap of fuel tank.
6) Lower down the fuel tank slowly
as support the tank by tray

(II) Check

1. Check the fuel tank assy
1) Check if it has damage or severe deformation of fuel tank surface.

(III) Installation

1. Install the fuel tank assy
1) Hoist the tank to the installation position and install the front and rear strap and tighten the bolts
for fixing the tank.

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2) Connect the fuel tank tube with the tube
inside fender

3) Connect the fuel filling tube with tank and
tighten the clamp

4) Connect the wires connector

5) Install the access cap of fuel tank

2. Install the rear seat cushion assy
3. Descend the car
4. Connect the cathode wire of battery
5. Close the engine hood.

S2-

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V. Fuel evaporation nylon tube assy

(I) Disassembly

1. Open the engine hood
2. Release the fuel system pressure
3. Disconnect the cathode wire of battery.
4. Dismantle the rear seats cushion assy
5. Dismantle the fuel tank assy
6. Dismantle the fuel evaporation nylon tube assy
1) Disconnect the fuel evaporation nylon tube assy with the fuel tank.
2) Take down the fuel evaporation nylon tube assy

(II) Installation

1. Install the fuel evaporation nylon tube assy
1) Connect the fuel evaporation nylon tube assy with the fuel tank

2. Install the fuel tank assy
3. Install the rear seat cushion assy
4. Connect the cathode wire of battery
5. Close the engine hood

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Engine ignition system 163

VI. Fuel inlet nylon tube assy

(I) Disassembly

1. Open the engine hood
2. Release the fuel system pressure
3. Disconnect the cathode wire of battery.
4. Dismantle the rear seats cushion assy
5. Dismantle the fuel tank assy
6. Dismantle the fuel inlet nylon tube assy
1). Disconnect the fuel inlet nylon tube assy with fuel filter

2) Disconnect the fuel inlet nylon tube assy with fuel
tank.
3) Take down fuel inlet nylon tube assy.

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(II) Installation

1. Install fuel inlet nylon tube assy
1) Connect the fuel inlet nylon tube with fuel tank

2) Connect the fuel inlet nylon tube
with fuel filter

2. Install the fuel tank assy
3. Install the rear seat cushion assy
4. Connect the cathode wire of battery
5. Close the engine hood

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Engine ignition system 165

VII. Fuel return nylon tube assy

(I) Disassembly

1. Open the engine hood
2. Release the fuel system pressure
3. Disconnect the cathode wire of battery.
4. Dismantle the rear seats cushion assy
5. Dismantle the fuel tank assy
6. Dismantle the fuel return nylon tube assy
1) Disconnect the fuel return nylon tube with fuel tank
2) Take down the fuel return nylon tube assy.

(II) Installation

1. Install fuel return nylon tube assy
1) Connect the fuel return nylon tube with fuel tank assy

2. Install
the fuel

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tank assy
3. Install the rear seat cushion assy
4. Connect the cathode wire of
battery
5. Close the engine hood

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VIII. Fuel delivery pump assy

(I) Disassembly

1. Open the engine hood
2. Release the fuel system pressure
3. Disconnect the cathode wire of battery.
4. Dismantle the rear seats cushion assy
5. Dismantle the fuel delivery pump assy
1) Pry up the access cap of fuel tank by the slot screwdriver.

2) Disconnect the wires connector of fuel delivery
pump
Attention: Do not use any tool to disconnect the
joint
Attention: Cover the junction place by plastic bag
in case of other impurities getting inside.

3) Loosen the snap ring of fuel pump by the
special tool

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4) Take down the flang sealing ring of fuel pump

5) Take out the fuel pump
Attention: Please maintain at the skew position
when take out the fuel pump so as to avoid
damaging the fuel level sensor.

(II) Check

1. Check the fuel delivery pump assy
1). Check if it has damage or fuel particles, if has, clean or change it.
2). Resistance check.Connect the 2 pins at the right side of connector on pump then measure the
resistance value of the fuel level sensor at the lowest and highest condition, the lowest resistance
value is 200Ω±5Ω and the highest resistance value is 25Ω±3Ω.
3). Do not keep running for long time to avoid pump core damage.

2. Check Y sealing ring

1) Check if it has rupture or defects.

3. Check the fixed snap ring of pump
1). Check if it has deformation, crack, defects, damage
and check if the mounting thread has damage.
4. Check the fuel level sensor
1). Check if the floater has deformation and if its surface
has dirts

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(III) Installation

1. Install
fuel delivery pump assy
1) Put the pump inside fuel tank
Attention: Put in the pump at a skew position and make sure the
Assembly direction is correct.

2) Install the flange sealing ring of fuel pump
Attention: The sealing ring needs to be matched with fuel tank completely and without turnup.

3). Install the fixed snap ring of fuel pump
Tighten torque: 75N.m±5N·m
Attention: Please pre-tighten and then screw it tightly