NO.19 EXHAUST SMOKE [MZR 1.5, MZR 1.6]


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19

EXHAUST SMOKE

DESCRIPTION
•  Blue, black, or white smoke from exhaust system.
POSSIBLE CAUSE
Blue smoke (Burning oil):
•  PCV valve malfunction
•  Engine internal oil leakage
White smoke (Water in combustion):
•  Cooling system malfunction (coolant loss)
•  Engine internal coolant leakage
Black smoke (Rich fuel mixture):
•  Air cleaner restriction
•  Intake-air system is collapsed or restricted
•  Fuel return line is restricted
•  Continuous memory DTC is stored
•  Injector fuel leakage
•  Excessive fuel pressure
•  Spark plug malfunction
•  CMP sensor malfunction
•  PCM malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:
•  Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
•  Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the "BEFORE SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this manual. (See BEFORE SERVICE PRECAUTION [MZR 1.5, MZR 1.6].) (See AFTER SERVICE PRECAUTION [MZR 1.5, MZR 1.6].)
Caution
•  If there is foreign material on the connecting area of the quick release connector, it might damage the connector or fuel pipe. To prevent this, disconnect the connector and clean the connecting area before connecting.

Diagnostic procedure

STEP

INSPECTION

ACTION

1
What color is smoke coming from the exhaust system?
Blue
Burning oil is indicated.
•  Go to the next step.
White
Water in combustion is indicated.
•  Go to Step 3.
Black
Rich fuel mixture is indicated.
•  Go to Step 4.
2
Inspect the PCV valve operation.
Is there any malfunction?
Yes
Replace the PCV valve.
No
Inspect the following:
•  Blocked oil drain passage in cylinder head
•  Damaged cylinder bore
•  Damaged valve guide, stems or valve seals
•  Piston ring is not seated, seized or worn
Repair or replace the malfunctioning part according to the inspection results.
•  If other drivability symptoms are present:
―  Return to diagnostic index to service any additional symptoms.
3
Does the cooling system hold pressure?
Yes
Inspect the following:
•  Cracked or porous engine block
•  Cylinder head gasket leakage
•  Intake manifold gasket leakage
Repair or replace the malfunctioning part according to the inspection results.
•  If other drivability symptoms are present:
―  Return to diagnostic index to service any additional symptoms.
No
Inspect for cause.
4
Inspect the following:
•  Air cleaner restriction
•  Collapsed or restricted intake-air system
•  Restricted fuel return line
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 4.
No
Go to the next step.
5
Connect the M-MDS to the DLC-2.
Perform the KOEO or KOER self test.
Are any continuous memory DTCs present?
Yes
Go to the appropriate DTC inspection.
No
Go to the next step.
6
Install the fuel pressure gauge between the fuel pipe and the fuel distributor.
Start the engine and idle it.
Measure the fuel line pressure during idle.
Is the fuel line pressure correct during idle?
Yes
Go to the next step.
No
Low:
•  Inspect the fuel line for clogging.
―  If there is no malfunction:
•  Replace the fuel pump unit.
―  If there is a malfunction:
•  Repair or replace the malfunctioning part according to the inspection results.
High:
•  Replace the fuel pump unit.
7
Perform the Spark Test.
Is the strong blue spark visible at each cylinder?
Yes
Inspect the CMP sensor.
Replace the CMP sensor, if necessary.
No
Repair or replace the malfunctioning part according to the inspection results.
8
Verify the test results.
•  If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 1.5, MZR 1.6].)
•  If malfunction remains, inspect related Service information perform repair or diagnosis.
―  If vehicle repaired, troubleshooting completed.
―  If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)