NO.19 EXHAUST SMOKE [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))


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 is restricted. • Intake-air system 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 "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual. (See BEFORE SERVICE PRECAUTION [AJ].) (See AFTER SERVICE PRECAUTION [AJ].)


STEP	INSPECTION		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 rings are not seated, seized or worn. • Damaged cylinder bore - If other drivability 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 • Engine block cracks or porosity - If other drivability 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 normal?	Yes	Go to next step.
4		No	Service as necessary. Repeat Step 4.
5	• Connect WDS or equivalent to DLC-2. • Turn ignition switch on. • Retrieve any DTC. • Is "PASSED" displayed?	Yes	No DTC displayed: • Go to next step.
5		No	DTC displayed: • Go to appropriate DTC test.
6	• Install fuel pressure gauge between fuel filter 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 [AJ].)	Yes	Go to next step.
6		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	• Perform spark test. (See Spark Test.) • Is strong blue spark visible at each cylinder?	Yes	Inspect spark plugs and CMP sensor.
7		No	Repair or replace malfunctioning part according to spark test results.
8	• 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 or reprogram PCM.