NO.18 EXHAUST SMOKE [F2]

id010394851100

18

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.
•  Excessive fuel pressure
•  Improper engine compression
•  Injector fuel leakage
•  Ignition system 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.

Diagnostic procedure

STEP

INSPECTION

RESULTS

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
Remove and shake the PCV valve.
Does the PCV valve rattle?
Yes
Inspect for the following:
•  Damaged valve guide, stems or valve seals
•  Blocked oil drain passage in cylinder head
•  Piston ring is not seated, seized or worn.
•  Damaged cylinder bore
If other drivability symptoms are present, return to diagnostic index to service any additional symptoms.
No
Replace the PCV valve.
3
Does the cooling system hold pressure?
Yes
Inspect for the following:
•  Cylinder head gasket leakage
•  Intake manifold gasket leakage
•  Cracked or porous engine block
If other drivability symptoms are present, return to diagnostic index to service any additional symptoms.
No
Inspect for cause.
4
Inspect for the following:
•  Air cleaner restriction
•  Collapsed or restricted intake-air system
•  Restricted fuel return line
Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 4.
5
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position. Retrieve any DTC.
Is “NO CODES RECEIVED” or “SYSTEM PASSED” displayed?
Yes
No DTC is displayed:
Go to the next step.
No
DTC is displayed:
Go to appropriate DTC test.
6
Install fuel pressure gauge between the fuel pipe and the fuel distributor.
Start the engine and idle it.
Measure fuel line pressure during idle.
Is fuel line pressure correct during idle?
(See FUEL PUMP UNIT INSPECTION [F2].)
Yes
Go to the next step.
No
Zero or Low:
•  Inspect fuel pump circuit
•  Inspect for open fuel pump relief valve
•  Inspect for fuel leakage inside pressure regulator
•  Inspect for clogged main fuel line
High:
•  Inspect pressure regulator for high pressure cause
•  Inspect for clogged fuel return line
7
Does fuel line pressure remain at specification for 60 sec when the ignition switch is turned to the ON position?
(See FUEL PUMP UNIT INSPECTION [F2].)
Yes
Go to the next step.
No
Inspect pressure regulator for high pressure cause.
8
Is strong blue spark visible at each disconnected high-tension lead while cranking engine?
Yes
Inspect spark plugs.
No
Inspect following:
•  High-tension leads
•  Ignition coil and connector
9
•  Verify test results.
―  If normal, return to diagnostic index to service any additional symptoms.
―  If malfunction remains, inspect related Service Information and perform repair or diagnosis.
•  If vehicle is repaired, troubleshooting completed.
•  If vehicle is not repaired or additional diagnostic information is not available, replace the PCM.