Kia Carens. Instruction — part 79

10

Check spark plug condition.
Spark plug gap : 0.027~0.031 in (0.7~0.8mm)
Check for exessive carbon deposit and correct
contact with spark plug wires. Are spark plugs
OK?

Yes

Go to next step.

No

Clean or replace.

11

Replace ECM and check for proper operation.

6

Cranks normally, but hard to start - When engine is cold

Description

· Cranks normally, but cranking time up to starting is excessively long
· Battery is OK
· Restart is normal after engine warmed up
· Engine is normal while engine is idling (Refer to "Rough Iding" if not in good idling condition)

(Troubleshooting hint)
1. Overrich air/fuel ratio
· Malfunction of manifold absolute pressure sensor
· Contaminated air cleaner element
2. Overlean air/fuel ratio
· Malfunction of injection control (Correction for engine coolant temperature)

Step

Check

Action

1

Check if malfunction indicator light is
illuminated while ignition switc in ON.
Is MIL illuminated longer than 3 seconds after
ignition switch is turned ON?

Yes

Malfunction indicator light is illuminated.
Check for causes. Refer to troubleshooting
with diagnostic trouble codes. page 21-18.

No

Go to next step.

2

Check terminal voltage of mass air flow
sensor, throttle position sensor, ignition coils,
engine coolant temperature sensor.
Are sensors OK?

Yes

Go to next step.

No

Check for causes.

3

Check if engine starts easily when throttle
valve is held one quarter open.
Does engine start easily?

Yes

Check carbon deposit on throttle valve and go
to step 6.

No

Go to next step.

4

Check vacuum in intake manifold while engine
is idling.
Vacuum : more than 18.9 in.Hg (480 mmHg)
Is intake manifold vacuum within specification?

Yes

Go to next step.

No

Check air leakage at intake air system
component.

5

Check cleanness of air cleaner element.
Is air cleaner element OK?

Yes

Go to next step.

No

Replace air cleaner element.

6

Connect the data link connector terminals fuel
pump and B+ with a jumper wire and check
fuel line pressure while ignition switch is ON.
Fuel line pressure : 40~51 psi (320~350 kPa,
3.2~3.5 kg/cm²)
Is fuel line pressure within specification?

Yes

Go to next step.

No

High pressure :
Disconnect return line from filter side.
Blow through line towards tank.
If line is clear, try with new pressure regulator.
If line is blocked, check for blockage in return
line and clean or replace as necessary

Low pressure :
Clamp return line and check if pressure rises.
If pressure rises, replace pressure regulator.
If pressure does not rise, check fuel filter at
fuel delivery module.
If it is OK, measure fuel pump max.
Pressure and replace as necessary.

7

Replace ECM and check for proper operation.
Is system operating correctly?

Yes

Road test and return vehicle to customer.

No

Replace fuel with another brand.

7

Cranks normally, but hard do start-After engine is warmed up

Descirtion

· After engine is left hot after running, cranks normally, but cranking time up to starting is excessively long
· Battery is OK
· Starts normally when engine is cold
· Engine is normal while engine is idling (Refer to "Rough ldling" if not in good idling condition)

(Troubleshooting hint)
1. Overrichair/fuel ration
· Malfunction of fuel ignition control
· Fuel leakage from injector
2. Vapor lock
· Fuel leakage from injector

Step

Check

Action

1

Check that malfunction indicator light is
illuminated while ignition switch is ON.
Is MIL illuminated longer than 3 seconds after
ignition switch is turned ON?

Yes

Malfunction indicator light is illuminated.
Check for causes. Refer to troubleshooting
with diagnostic trouble codes, page 21-18.

No

Go to next step.

2

Check terminal voltage of manifold absolute
pressure sensor, throttle position sensor,
ignition coils and engine coolant temperature
sensor.
Are sensors OK?

Yes

Go to next step.

No

Check for causes.

3

After engine idling and turn ignition switch OFF.
Check that fuel line pressure is retained.
Fuel line pressure : more than 25 psi (180 kPa,
1.8 kg/cm²) for 5 minutes
Is fuel line pressure retention within
specification?

Yes

Go to next step.

No

Plug outlet of fuel pressure regulator and turn
ignition switch OFF. Then check that fuel line
pressure is kept.
- If normal : replace fuel pressure regulator
- If not normal : check fuel pump pressure kept.
If fuel pump is normal, check fuel leakage from
injector.

4

Warm up engine to normal operating
temperature and stop engine. Connect the
data link connector terminals FUEL PUMP and
B+ with a jumper wire for 3 minutes while
ignition switch is ON. Then check that engine
starts easily.
Does engine start easily?

Yes

Replace fuel with another brand.

No

Go to next step.

5

Replace ECM and check for proper operation
operation.
Is system operating correctly?

Yes

Road test and return vechcle to customer.

No

Replace fuel with another brand.

8

Rough idling/Engine stops while idling - Always

Description · Engine starts normally, but engine stops or vibrates while idling.

(Troubleshooting hint)
1. Overrich air/fuel ratio
· Air leakage
· Malfunction of fuel injection control
· Low fuel line pressure
2. Clogging or malfunction of one or more injector
3. Malfunction of manifold absolute pressure sensor
4. Malfunction of IAC valve or related wiring
5. Malfunction of spark plug
6. Low engine compression pressure

7. Malfunction of throttle position sensor or related wiring

Step

Check

Action

1

Check that malfunction indicator light is
illuminated while ignition switch is ON.
Does the MIL illuminated longer than 3
seconds after ignition switch is turned ON?

Yes

Malfunction indicator light is illuminated.
Check for causes. Refer to Troubleshooting
with diagnostic trouble codes, page 21-18.

No

Go to next step.

2

Check terminal voltage of mass air flow
sensor, throttle position sensor, ignition coils,
engien coolant temperature sensor.
Are sensor OK?

Yes

Go to next step.

No

Check for causes.

3

Check operating sound of injector while engine
idling.
Are injectors operating?

Yes

Go to step 5.

No

Go to next step.

4

Check that approx. battery voltage is applied
on injector connector while ignition switch is
ON (approx. 12V).
Is voltage within specification?

Yes

Go to next step.

No

Check the wiring harness between ECM and
injector.

5

Check the resistance of injector.
Resistance : 14.5Ω
Is resistance within specification?

Yes

Go to next step.

No

Replace injector.

6

Ignition ON, throttle closed, measure voltage
of throttle position sensor (0.3~0.7V).
Is voltage within specification?

Yes

Go to next step.

No

Replace throttle position sensor or repair
wiring harness.

7

Check MAF sensor and related DTC.
Is MAF sensor OK?

Yes

Clean or replace.

No

Go to next step.

8

Check engine compression pressure.
Engine compression pressure : 193 psi (1360
kPa, 13.6 kg/cm²) - 300 rpm
Is engine compression pressure within
specification?

Yes

Go to next step.

No

Check engine condition.
- Wear of piston, piston ring and cylinder wall
- Defect of cylinder head gasket
- Deformation of cylinder head
- Valve stuck to guide

9

Replace ECM and check for proper operation.

9

Rough idling / Engine stops while engine is idling - Engine cold

Description · Engine speed is slow, engine stops or vibrates while warming up engine.

(Troubleshooting hint)
1. Insufficient intake air.
· Malfunction of manifold absolute pressure sensor
· Clogged air cleaner element
· Malfunction of IAC valve
2. Malfunction of fuel injection control.
· Malfunction of fuel injection control devices
(correction for engine coolant temperature)

Step

Check

Action

1

Check that malfunction indicator light is
illuminated while ignition switch is ON.
Is MIL illuminated longer than 3 seconds after
ignition switch is turned ON?

Yes

Malfunction indicator light is illuminated.
Check for causes. Refer to troubleshooting
with diagnostic trouble codes, page 21-18.

No

Go to next step.

2

Check air leakage at intake system and
vacuum of dynamic chamber while engine is

Yes

Go to next step.

idling.
Vacuum : 18.9 in.Hg (480 mmHg) at idle
Is intake manifold vacuum within specification?

No

Check air leakage at intake system.

3

Check cleanness of air cleaner element.
Is air cleaner element OK?

Yes

Go to next step.

No

Replace air cleaner element.

4

Check terminal voltage of mass air flow
sensor, throttle position sensor, ignition coils,
engine coolant temperature sensor.
Are sensors OK?

Yes

Go to next step.

No

Check for causes.

5

Check resistance of engine coolant
temperature sensor.
· At -4°F(-20°C) : 14.6 to 17.8 kΩ
· At 68°F(20°C) : 2.2 to 2.7 kΩ
· At 176°F(80°C) : 0.29 to 0.35 kΩ
Is resistance within specification?

Yes

Go to next step.

No

Road test and return vehucle to customer.

6

Replace ECM and check for peoper operation.
Is system operating correctly?

Yes

Road test and return vehicle to customer.

No

Replace fuel with another brand.

10

Rough idling/Engine stops while engine is idling - After engine is warmed up

Description · Engine operation is normal while warming up engine, but engine stops or vibrates after warming up.

(Troubleshooting hint)
1. Malfunction of IAC valve
2. Overlean air/fuel ratio
· Air leakage
· Low fuel line pressure
3. Malfunction of ignition system
4. Overrich air/fuel ratio
· Malfunction of fuel injection control
(correction for coolant temperature)
5. Low engine compression pressure

Step

Check

Action

1

Check that malfunction indicator light is
illuminated while ignition switch is ON.
Is MIL illuminated longer than 3 seconds after
ignition switch is turned ON?

Yes

Malfunction indicator light is illuminated.
Check for causes. Refer to troubleshooting
with diagnostic trouble codes, page 21-18.

No

Go to next step.

2

Check terminal voltage of mass air flow
sensor, throttle position sensor, ignition coils,
engine coolant temperature sensor.
Are sensors OK?

Yes

Go to next step.

No

Check for causes.

3

Check vacuum of intake manifold.
Vacuum : more than 18.9 in.Hg (480 mmHg) at
idle

Yes

Go to next step.

No

Check for air leakage at intake system
component.

4

Check cleanness of air cleaner element.
Is air cleaner element OK?

Yes

Go to next step.

No

Replace air cleaner.

5

Check fuel line pressure while engine is idling.
Fuel line pressure : 46~51 pai (320~350 kPa,
3.2~3.5 kg/cm²)
Is fuel line pressure within specificaiton?

Yes

Go to next step.

No

High pressure :
Disconnect return line from filter side.
Blow through line towards tank.
If line is clear, try with new pressure regulator.
If line is blocked, check for blockage in return
line and clean or replace as necessary.