2007 ISUZU KB P190 fuel consumption

TROUBLESHOOTING 6 – 1




BASIC INSPECTION PROCEDURE....6– 2

1. HARD STARTING ............................6– 3

1-1.Starter Motor Inoperative ..........6– 3

1-2. Starter Motor Operates But
Engine Does Not Turn Over ...........6– 3

1-3. Engine Turns Over But Does
Not Start Engine ..............................6– 4

2. UNSTABLE IDLING .........................6– 5

3. INSUFFICIENT POWER ..................6– 6

4. EXCESSIVE FUEL
CONSUMPTION..................................6– 7

5. EXCESSIVE OIL CONSUMPTION ..6– 8

6. OVERHEATING ...............................6– 9

7. WHITE EXHAUST SMOKE..............6– 9

8. DARK EXHAUST SMOKE ...............6– 10

9. OIL PRESSURE DOES NOT RISE..6– 11

10. ABNORMAL ENGINE NOISE ........6– 12

10-1. Engine Knocking ....................6– 12

10-2. Gas Leakage Noise .................6– 12

10-3. Continuous Noise ...................6– 13

10-4. Slapping Noise ........................6– 13

10-5. Excessive Turbocharger
Noise ................................................6– 14
11. ROTATING PART WEAR OF
TURBOCHARGER.............................. 6– 14

12. OIL LEAKAGE FROM
TURBOCHRGER ................................ 6– 15

13. INSUFFICIENT ACCELERATION
AND/OR LACK OF POWER DUE
TO TURBOCHARGER........................ 6– 15

14. BATTERY CHARGING AND
NOISE PROBLEM .............................. 6– 16

14-1. Battery No Charging ............... 6– 16

14-2. Battery Overcharging ............. 6– 16

14-3. Battery Under Charging ......... 6– 17

14-4. Battery Unstable Charging
Current ............................................. 6– 17

14-5. Charging System Noise ......... 6– 18

15. STARTER MOTOR PROBLEM ..... 6– 19

15-1. Starter Motor Pinion Engages
to Ring Gear But Engine Does
Not Turn Over .................................. 6– 19

15-2. Incorrect Pinion And Ring
Gear Engagement ........................... 6– 19

15-3. Starter Motor Continues To
Run After The Starter Switch Is
Turned Off........................................ 6– 20

15-4. Excessive Commutator
Sparking .......................................... 6– 20


SECTION 6
TROUBLESHOOTING
TABLE OF CONTENTS
PAGE PAGE

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ISUZU KB P190 2007

TROUBLESHOOTING 6 – 7
4. Excessive Fuel Consumption
Step Action Value(s) Yes No
1 Was the air cleaner element clogged? — Clean or
replace the air cleaner
element. Go to Step 2
2 Was the air leakage found from the air intake side of
the turbocharger? —
Repair or
replace the air intake side of the
turbocharger. Go to Step 3
3 Was the turbocharger working completely? —
Go to Step 4 Replace the
turbocharger
4 Was there the fuel leakage? — Repair or
replace the fuel leakage part. Go to Step 5
5 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at 200 rpm
Go to Step 6 Readjust the
valve clearance or replace the cylinder head gasket or
cylinder liner or
piston or piston ring or valve
and valve seat
6 Was the injection nozzle pressure or spray pattern normal? —

Go to Step 7 Replace the
injection nozzle
7 Are any DTC stored? — Go to indicated
DTC Solved


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ISUZU KB P190 2007

6F – 16 EXHAUST SYSTEM
GENERAL DESCRIPTION


036LV002

The turbocharger internal mechanism consists of the turbine wheel, the compressor wheel, and the radial bearings.
These parts are supported by the bearing housing.
The turbocharger external mechanism consists of the compressor housing air intake port and the turbine housing
air exhaust port.
The turbocharger increases air intake efficiency. This results in increased engine power, reduced fuel consumption,
and minimal engine noise.
The turbocharger operates at very high speeds and temperatures. Part materials have been carefully selected and
machined to extremely high precision.
Turbocharger servicing requires great care and expertise.
If reduced performance is noted, check the engine for damage or wear. If there is no apparent engine damage or
wear, trouble with the turbocharger is indicated.

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6A-10 ENGINE MECHANICAL (4JK1/4JJ1)
Excessive white exhaust smoke
Condition Possible Cause Correction
Bad injection timing Engine control system malfunction System diagnosis
Defective sensor Replace sensor
Control unit malfunction Replace unit
Malfunction detected by engine
control system
Engine control system malfunction System diagnosis
Excessive valve clearance Adjust clearance
Sticking valve stem (valve open) Repair or replace valve
Damaged valve spring Replace spring
Valve seat abrasion Repair valve seat
Compression leakage due to
damaged piston ring Replace piston ring
Damaged gasket
Replace gasket
Insufficient compression pressure
Piston scoring Replace piston
Fuel condition W ater in fuel Drain existing fuel and replace with
new fuel
W orn or damaged piston ring(s) Replace ring(s)
Defective valve stem oil seal Replace oil seal
Defective turbocharger oil seal Replace turbocharger
Excessive oil consumption
Clogged turbocharger oil return
pipe Repair pipe

Engine knocking
Condition Possible Cause Correction
Bad timing Engine control system malfunction System diagnosis
Defective sensor Replace sensor
Control unit malfunction Replace unit
Malfunction detected by engine
control system
Engine control system malfunction System diagnosis
Fuel condition Poor quality fuel Drain existing fuel and replace with
new fuel
Clogged air cleaner element Clean or replace element
Clogged intake pipes Clean or replace pipes
Poor engine aspiration
Engine control system malfunction System diagnosis
Foreign material in cylinders Engine overhaul Engine break-down Scored pistons and/or bearings Replace pistons and/or bearings


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6E-16 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Gauges
RTW76EXF004701
Fuel
consumption
signal
output
11 676
8
7 5 B-56
C-107 8 B-24
17
0.3
BLK/
YEL
0.5
YEL
0.5
YEL
0.5
YEL
0.5
BLK
0.85
BLK 6
7 0.5
BLK/
YEL 0.5
BLK/
YEL
0.5
BLK/
YEL 0.5
BLK/
YEL 0.5
BLK/
YEL
0.5
BLK/
YEL 0.5
BLK
0.85
BLK
0.85
BLK
0.85
BLK
0.85
BLK 0.5
BLK
0.5
BLK0.5
WHT
0.5
BLK/
RED
0.3
BLK/
RED
20
13
23 0.3
YEL/
RED
0.3
YEL/
RED 0.5
YEL/
BLK
0.5
YEL/
BLK
0.5
YEL/
RED 0.5
YEL/
BLK
0.5
GRN/
RED
ECM(27)
ECM(26) 0.3
BLK/
RED
0.5
BLK/
RED
4
20.3
ORN/
WHT
0.5
ORN/
WHT
Fuel
tank
sender
unit
10 C-94
TCM
Engine
speed
signal
inputTCM
7 C-94
62 C-58 A/T
Engine
speed
signal
output
33 IP
cluster
70 B-23
B-24
B-23
H-18
H-4
12
5
H-9
F-2
F-2
3
22 E-41
31
H-4
2 H-6
H-4 M/T
A/T 4WD
A/T 2WD
10
H-15
E-10
E-10 4
C-58
ECT
sensor
VSS
E-44
E-44
1
2 3
C-14
Meter
10A
Fuse/
relay
box
(Cabin) Speedometer
Fuel gaugeEngine coolant
temperature gauge
Tachometer Multi display
ECM
Signal
ECM
+B VSS
signal
output

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ENGINE CONTROL SYSTEM (4JK1/4JJ1) 6E-33
Pin No. Wire ColorPin Function
43 — Not used
44 RED/ WHT Starter switch signal
45 BLU/ RED ECM main relay control
46 — Not used
47 — Not used
48 — Not used
49 GRN/ YEL Cruise set lamp control
50 GRN/ WHT Cruise main lamp control
51 — Not used
52 RED/ WHT Battery voltage (Back-up)
53 — Not used
54 ORN/ BLK Fuel pump relay control
55 GRY/ RED A/C compressor relay control
56 RED/ WHT Accelerator pedal position signal
output
57 BRN/ YEL MIL control
58 — Not used
59 — Not used
60 — Not used
61 — Not used
62 BLK/ YEL VSS signal
63 BLK Ground
64 — Not used
65 BLU/ RED ECM main relay control
66 YEL CAN High
67 BLU CAN Low
68 — Not used
69 BRN/ RED Fuel filter lamp control
70 ORN/ WHT Fuel consumption signal output
71 PNK/ WHT SVS lamp control (Euro 4
specification)
72 WHT/ GRN Ignition voltage
73 RED/ BLU Battery voltage

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6E-364 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Fuel Injection System Description
Fuel Injection Quantity Control
This control determines the fuel injection quantity by
adding coolant temperature, fuel temperature, intake
air temperature, barometric pressure, mass air flow and
some switch inputs information corrections to the basic
injection quantity is calculated by the ECM based on
the engine operating conditions (engine speed,
accelerator pedal pressing amount and boost pressure
sensor). More fuel rate indicates if the engine load is
increased as the accelerator pedal is stepped on at
constant engine speed.
Combined with high pressure injection of atomized fuel,
this control improves exhaust gas and ensures proper
fuel consumption. Compared with conventional
mechanical governors, an electronic control system
provides higher degree of freedom of fuel injection
quantity control, thereby presenting high accelerator
response (acceleration feeling and pressing feeling).
Starting Injection Quantity Control
At the engine starting (after the key switch is turned to
the START position to start the engine, up to return of
key switch to the ON position), optimum fuel injection
quantity is controlled based on the information on the
engine speed and coolant temperature. At low
temperature, the fuel injection quantity increases.
When the engine started completely, this boosted
quantity mode at the starting is cancelled and normal
running mode is restored.
Idle Speed Control
A control is made so as to achieve stable idling speed
at all time regardless of engine secular changes or
engine condition variations. The ECM sets target idling
speed and controls the fuel injection quantity according
to the engine conditions (actual engine speed, coolant
temperature and engine load) to follow actual engine
speed to the target idling speed so as to ensure stable
idling speed.
Idle Vibration Control
A control is made so as to reduce the engine vibration
caused by torque variations between cylinders due to
variations in fuel injection quantity of each cylinder or
injector performance. The ECM corrects the injection
quantity between cylinders based on the revolution
signals from the crankshaft position (CKP) sensor.
Normal range of correction quantity between cylinders
is within ±5 mm
3.

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ENGINE DIAGNOSIS (C24SE) 6-1
SECTION 6
ENGINE DIAGNOSIS
TABLE OF CONTENTS
PAGE
Engine Diagnosis .............................................................................................................. 6- 2
Hard Starting ................................................................................................................. 6- 2
Engine Compression Test Procedure ......................................................................... 6- 3
Rough Engine Idling or Engine Stalling...................................................................... 6- 4
Rough Engine Running ................................................................................................ 6- 5
Hesitation ..................................................................................................................... . 6- 6
Engine Lacks Power ..................................................................................................... 6- 7
Engine Noisy ................................................................................................................. 6 - 8
Abnormal Noise Due to Hydraulic Lash Adjustor ...................................................... 6- 9
Troubleshooting Procedure ......................................................................................... 6- 9
Abnormal Combustion ................................................................................................. 6-11
Engine Oil Consumption Excessive............................................................................ 6-12
Fuel Consumption Excessive ...................................................................................... 6-13
Oil Problems.................................................................................................................. 6-13
Engine Oil Pressure Check .......................................................................................... 6-13
Malfunction Indicator Lamp ......................................................................................... 6-14


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