Is spark plug wet, covered with carbon
or grayish white?
carbon:
Inspect for fuel leakage from injector.
Spark plug is grayish white:
Inspect the fuel injector for clogging.
No
Install the spark plugs on original
cylinders.
Go to the next step.
20
Remove and shake the PCV valve.
Does the PCV valve rattle?
Yes
Go to the next step.
No
Replace the PCV valve.
21
visually inspect the exhaust system
part.
Is there any deformed exhaust system
part?
Yes
Replace the suspected part.
No
Go to the next step.
22
Install the fuel pressure gauge between
the fuel pipe and the fuel distributor.
Short check connector terminal F/P to
body GND using a jumper wiring.
Turn the ignition switch to the ON
position.
Is fuel line pressure correct when
ignition switch is turned on/off
five
times?
(see
FUEL LINE PRESSURE
INSPECTION [MZI-3.5]
.)
Yes
Go to the next step.
No
Zero or low:
Inspect the fuel pump relay and fuel
pump circuit.
Inspect the fuel line for clogging.
If there is no malfunction, replace the
fuel pump unit.
(see
FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.5]
.)
High:
Replace the fuel pump unit.
(see
FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.5]
.)
23
Visually inspect the fuel injector O-
ring and fuel line for fuel leakage.
Service if necessary.
Is the fuel line pressure held after the
ignition switch is turned off?
(see
FUEL LINE PRESSURE
INSPECTION [MZI-3.5]
.)
Yes
Go to the next step.
No
Inspect the fuel injector.
If the fuel injector is normal, replace the
fuel pump unit.
(see
FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.5]
.)
24
Disconnect the vacuum hose between
the purge solenoid valve and the intake
manifold from purge solenoid valve
side.
Plug opening end of vacuum hose.
Start the engine.
Is starting condition improved?
Yes
Inspect if the purge solenoid valve is
stuck open mechanically.
Inspect the evaporative emission control
system.
No
Go to the next step.
25
Is air leakage felt or heard at intake-air
system components while racing
engine to higher speed?
Yes
Repair or replace the malfunctioning
part.
No
Go to the next step.
2007 Mazda CX-9 Grand Touring
2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
Microsoft
Sunday, November 15, 2009 9:27:37 AM
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