Mazda CX-9 Grand Touring 2007 Manual page 889

2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
Black smoke (Rich fuel mixture):
POSSIBLE CAUSE
DIAGNOSTIC PROCEDURE
DIAGNOSTIC PROCEDURE
STEP INSPECTION
1 What color is smoke coming from the
exhaust system?
2007 Mazda CX-9 Grand Touring
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 servicing fuel
system:
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 [MZI-3.5] .)
(see AFTER REPAIR PROCEDURE [MZI-3.5] .)
CAUTION:
Disconnecting/connecting quick release connector without
cleaning it may 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.
RESULTS ACTION
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.