NO.15 EXCESSIVE BLACK SMOKE [WL-3]

id0103b5913500

15
Excessive black smoke
DESCRIPTION
•  Excessive black smoke is observed in the exhaust gas.
POSSIBLE CAUSE
•  Air cleaner element restriction
•  Incorrect fuel injection timing
•  Injection nozzle malfunction
•  Injection pump malfunction
•  Low engine compression
•  EGR System Malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
•  Connect M-MDS to DTC.
•  Turn the engine switch to the ON position (Engine off).
•  Retrieve any DTCs.
•  Is a DTC displayed?
Yes
DTC is displayed:
•  Go to the appropriate DTC test.
No
No DTC is displayed:
•  Go to the next step.
2
•  Does any other symptom exist?
Yes
Go to the appropriate flow chart.
No
Go to the next step.
3
•  Inspect the air cleaner element for clogging.
•  Is the air cleaner element normal?
Yes
Go to the next step.
No
Repair or replace the air cleaner element.
4
•  Inspect the injection timing.
•  Is the injection timing normal?
Yes
Go to the next step.
No
Inspect the TCV.
(See TIMER CONTROL VALVE (TCV) INSPECTION [WL-3].)
If the TCV is normal, adjust the injection timing.
5
•  Remove the injection nozzle.
•  Inspect the injection nozzle for the following:
―  Clogged nozzle
―  Seized needle valve
―  Incorrect valve opening pressure
―  Malfunctioning nozzle gasket
•  Is the injection nozzle normal?
Yes
Go to the next step.
No
Repair or replace the injection nozzle.
6
•  Perform the EGR system inspection.
•  Is the EGR system normal?
Yes
Go to the next step.
No
Inspect the following:
•  EGR solenoid (vent)
•  EGR solenoid (vacuum)
•  EGR valve
•  Vacuum hose connections
•  Wiring harness between EGR solenoids and PCM terminals
Repair or replace if necessary.
7
•  Measure the engine compression.
•  Is the compression normal?
Yes
Inspect the following:
•  Boost sensor
•  Injection pump
No
Inspect the following:
•  Damaged valve seat
•  Worn valve stem and valve guide
•  Worn or stuck piston ring
•  Worn piston, piston ring or cylinder
Service if necessary.
8
•  Verify the test results. If normal, return to the diagnostic index to service any additional symptoms.