NO.19 EXHAUST SMOKE [L3]


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. • Excessive fuel pressure • Improper engine compression • Injector fuel leakage • Ignition system malfunction Warning The following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read following warnings before performing 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 "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual. (See BEFORE REPAIR PROCEDURE [L3].) (See AFTER REPAIR PROCEDURE [L3].) Caution • Disconnecting/connecting quick release connector without cleaning it may possibly cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.


STEP	INSPECTION	RESULTS	ACTION
1	What color is smoke coming from exhaust system?	Blue	Burning oil is indicated. Go to 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 PCV valve. Does PCV valve rattle?	Yes	Inspect for 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 driveability symptoms are present, return to diagnostic index to service any additional symptoms.
2	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
3	Does cooling system hold pressure?	Yes	Inspect for following: • Cylinder head gasket leakage • Intake manifold gasket leakage • Cracked or porous engine block If other driveability symptoms are present, return to diagnostic index to service any additional symptoms.
3	Does cooling system hold pressure?	No	Inspect for cause.
4	Inspect for following: • Air cleaner restriction • Collapsed or restricted intake-air system • Restricted fuel return line Are all items okay?	Yes	Go to next step.
4		No	Service as necessary. Repeat Step 4.
5	Connect WDS or equivalent to DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
5		No	No DTC is displayed: Go to next step.
6	Install fuel pressure gauge between fuel pipe and fuel distributor. Start engine and run it at idle. Measure fuel line pressure at idle. Is fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION [L3].)	Yes	Go to next step.
6		No	Zero or low: • Inspect for clogged fuel line. • If okay, replace fuel pump unit. High: • Replace fuel pump unit.
7	Is strong blue spark visible at each disconnected high-tension lead while cranking engine?	Yes	Inspect spark plugs and CMP sensor.
7		No	Inspect following: • High-tension leads • Ignition coil and connector
8	Verify test results. • If okay, return to diagnostic index to service any additional symptoms. • If malfunction remains, replace PCM.