JAC S2. Engine. Service Manual

Engine ignition system

Engine ignition system 186

very important input signal and the ignition system is not able to work when the ECM fails to receive

this signal.

(III) Technical and service data

Service data

Ignition

wire

Primary coil
resistance

0.77 ～ 0.95Ω

Spark

Ignition

plug

clearance

0.7 ～ 0.8mm

(IV) Torque data

Important components torque table

Item

Torque (N·m)

Remarks

1 Ignition plug

25 ～ 30

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Engine ignition system

Engine ignition system 187

II. Failure diagnosis

(I) Diagnosis analysis table

SN Failure

phenomenon

Failure causes analysis

Solution

Remarks

Engine can’t start

or start difficultly

Ignition coil or ignition

switch failure

Check or replace the ignition

coil or ignition switch

Ignition plug failure

Check or replace the ignition

plug

High voltage wire breaks off

or unconnected

Check the high voltage wire

Unstable idling

High voltage wire or

ignition plug failure

Check or replace the high

voltage wire or ignition plug

Ignition coil failure

Check or replace the ignition

coil

Engine in

viberation or lack

of power in

acceleration

High voltage wire failure

Check or replace the high

voltage wire

Ignition plug failure

Check or replace the ignition

plug

Poor fuel

economy

Ignition plug failure

Check or replace the ignition

plug

(II) Diagnosis procedures table

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Engine ignition system

Engine ignition system 189

III. Ignition lock assy

(I) Disassembly

1. Open the engine hood
2. Disconnect the cathode wire of battery
3. Dismantle the driver’s airbag assy
4. Dismantle the steering wheel assy
5. Dismanlte the upper and down shell of steering column
6. Dismantle the clock spring
7. Dismantle the combination switch
8. Dismantle the anti-theft coil
9. Dismantle the ignition lock assy
1). Disconnect the wires connector of the ignition lock assy

2). Screw off the 2 nuts of
ignition switch assy
3). Take down the ignition
lock and its base

(II) Installation

1. Install the ignition lock assy

1). Screw into the 2 nuts of ignition lock and its

base tightly

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Engine ignition system

Engine ignition system 191

2). Connect the wires connector of ignition lock assy.

2. Install anti-theft coil
3. Install combination switch
4. Install clock spring
5. Install the upper and down
shell of steering column
6. Install steering wheel assy
7. Install the driver’s airbag
8. Connect the cathode wires
of battery
9. Close the engine hood

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Engine ignition system

Engine ignition system 192

IV. Ignition coil

(I.) Disassembly

1. Open the enginie hood
2. Disconnect the cathode wires of battery
3. Dismantle the ignition coil

1). Disconnect the wires connector of ignition coil

2). Screw off the 4 fixed bolts of ignition coil
and the wires bracket in engine compartment

3). Take down the ignition coil

(II.) Check

1. Ignition coil

Check the primary coil resistance between terminals, the value shall be 0.77~0.95Ω

(III) Installation

1. Install ignition coil

1). Smear little insulation grease on the head of ignition coil and install ignition coil.
2). Screw the fixed bolts of the ignition coil tightly

Tighten torque: (8±2)N·

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Engine ignition system

Engine ignition system 193

V. Ignition plug

(I) Disassembly

1. Open the engine hood
2. Disconnect the cathode wires of battery
3. Dismantle the ignition coil
4. Dismantle the ignition plug

1). Dismantle the ignition plug by the sleeve.

(II) Check

1. Check the ignition plug

a. Check if the thread or insulation body of the ignition plug has damage or rupture

b. Check if the ignition plug has carbod deposition or fuel/engine oil sediment. The normal
porcelain small head of ignition plug is between the white/slight yellow and gray or brown.

c. Check if the electrode of ignition plug has been damaged
d. Check the ignition plug clearance by the ruler. The standard value: 0.7~0.8mm.
e. Check the jump spark ability of ignition plug. Put the ignition plug on cylinder head and attach
the high voltage wires to the binding posts of the ignition plug, if it gives out the “pa-pa” sound
between the posts, it means the ignition plug works well and vice versa.

(III) Installation

1. Install ignition plug

1). Insert the ignition plug and tighten to the regulated torque by the special tool.

Tighten torque: 25~30Nm

2. Install the ignition coil
3. Connect the cathode wires of battery
4. Close the engine hood.

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Engine auxiliary exhausts system

Engine Mounting system 194

Engine auxiliary exhausts system

I. Overview

(I.) Structure overview

System diagram

Fuel evaporation and exhausts system

ฏܷ

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Engine auxiliary exhausts system

Engine Mounting system 195

Crankcase mandatory ventilation system

1. Air filter
2. Air inlet tube

3. Throttle valve body
4. Purification tank

5. PVC valve
6 Connection tube of PVC valve

7. Air inlet manifold
8. Injector

System description

Fuel evaporation and exhausts control system

The fuel steam recycling device is to recycle the gasoline steam inside the fuel tank and transfer

to air inlet tube of engine where mix with the fresh air and enter into cylinder for burning, by that

prevent gasoline steam from exhausting into air and causing pollution.

The fuel steam recycling device consists of the active carbon tank, solenoid valve of active
carbon tank, one-way valve and the relative steam tubes and vacuum tubes.

Crankcase mandatory ventilation system

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Engine auxiliary exhausts system

Engine Mounting system 196

The crankcase mandatory ventilation system is to send the cylinder blowby back to air inlet

manifold.

The carankcase mandatory ventilation valve (PCV) sends the cylinder blowby back to the air inlet

manifold. The air inlet manifold sucks into the crankcase blowby through PCV valve when the throttle

is partially opened. While the normal ventilator capacity of PCV valve is enough to suck in the blow

by and little ventilation air completely. The ventilation air is sucked into crankcase through air inlet

tube. During this process, the air comes through the connection tube of air inlet tube and rocker arm

cover. When the throttle is fully open, the vacuum degree of air inlet manifold is not enough for

opening PCV valve and sucking into crank blowby. The air will flow at a reverse direction through

connection tube. The PCV valve is not capable on the serious crank blowby cars because part air flows

into air inlet tube through connection tube under any circumstances.

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Engine auxiliary exhausts system

Engine Mounting system 197

(II) System theory

PCV valve working theory

Air inlet

manifold side without vacuum

2-w1179

ir inlet manifold side (High
vacuum)

Engine
Working conditions

Not

running

Engine working
conditions

Idling or decelaration

PCV valve

Not

workin

PCV valve

Fully open

Vacuum variation

Restri

cted

Slightly

Air inlet

manifold side
with suitable
vacuum

≊䰞ᇚ ࠙ם

Air inlet

manifold
side without
vacuum

≊䰞ᇚ ࠙ם

Engine
Working conditions

Normal

Engine working
conditions

Acceleration and high
speed poor performance

PCV valve

Normal

PCV valve

Work slowly

Vacuum variation

High

variation

Vacuum variation

Extremely high
variation

(III) Torque parameters

Key components torque table

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Engine auxiliary exhausts system

Engine Mounting system 198

Item

Torque (N·m)

Remarks

1 M6×20 E10 bolt

8.4±0.6

M6×20 E10

2 M6×12 E10 bolt

8.4±0.6

M6×12 E10

3 M6×45 E10 bolt

8.4±0.6

M6×45 E10

4 M6×25 E10 bolt

8.4±0.6

M6×25 E10

5 M6×12 E8 bolt

8.4±0.6

M6×12 E8

6 Oxygen sensor

35±5

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Engine auxiliary exhausts system

Engine Mounting system 199

Standard parts torque

Item

Torque (N·m)

Rem

arks

9 ～ 11

20 ～ 25

30 ～ 50

60 ～ 80

(IV) Service attention matters

Regular attention matters

1. Discharging engine coolant attention matters

1). after engine cooled down, then discharge the coolant.

2. Disconnect fuel tube attention matters

1). Before startring, make sure no flammable objects in the working area.
2). Release the fuel pressure before disconnection or disassembly.
3). Insert a plug in the front opening after disconnecting the joint.

3. Disconnection and disassembly attention matters

1). Work safely and follow the instructions and use the special tool according to the request.

2). Be careful with matching face and sliding face protection.

3). Use tape or something similar to seal the front opening of engine to prevent from impurities.
4). Lable and sort out the parts in order and category for the trouble shooting and re-assembly.

5). The principle for loosening bolts and nuts: Firstly loosen the one at the most outset then loosen
the one at its diagonal end and goes one in this sequence. If it has the designated loose sequence,
follow it.

4. Check, repair and replace attention matters

1). Check the part completely before repairing or replacing. Please change the part if necessary.

5. Assembly attention matters

1). Use the torque wrench to tighten nut and bolt.
2). The principle for tightening bolt and nut: Firstly tighten the central one by multi steps at the
same torque each time then tighten the ones at the inner and outer diagonal line. If it has
designated sequence for tightening, please follow it.

3). Replace with the new gasket, oil seal and O type ring.
4). Flush and clean and dry eack parts completely. Check if the engine oil or coolant tubes have
congestion.
5). Do not damage the matching face or sliding face. Clean the dust or scraps completely. Smear
the sliding face by engine oil before assembly.
6). Release the tube air firstly for re-charging engine coolant.

7).After repairing, running the engine and ratcheting up the RPM to check if the coolant, fuel,
engine oil and air inlet and outlet had leakage.

6. Parts needed to be tightened at a certain angle

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JAC S2. Engine. Service Manual - part 14