Mazda CX-9 Grand Touring 2009 Manual page 1330

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Visually inspect the CKP sensor and
teeth of crankshaft pulley.
16
Are CKP sensor and teeth of crankshaft
pulley normal?
Inspect the ignition coil related wiring
harness condition (intermittent open or
17
short circuit) for all cylinders. Are
wiring harness conditions normal?
Perform the spark test.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
18
3.7].)
Is strong blue spark visible at each
cylinder?
Inspect the spark plug conditions.
19 Is spark plug wet, covered with carbon
or grayish white?
Remove and shake the PCV valve.
20
Does the PCV valve rattle?
visually inspect the exhaust system part.
21 Is there any deformed exhaust system
part?
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
22 position.
Is fuel line pressure correct when
ignition switch is turned on/off five
times?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)
Visually inspect the fuel injector O-ring
and fuel line for fuel leakage.
2008 Mazda CX-9 Grand Touring
If CKP sensor and wiring harness are normal,
Yes Go to the next step.
No
Yes Go to the next step.
No
Yes Go to the next step.
No
Spark plug is wet or covered with carbon:
Inspect for fuel leakage from injector.
Yes
Spark plug is grayish white:
Inspect the fuel injector for clogging.
No
Yes Go to the next step.
No
Yes Replace the suspected part.
No
Yes Go to the next step.
No
Yes Go to the next step.
go to the next step.
Replace the malfunctioning part.
Repair the wiring harnesses.
Repair or replace the malfunctioning part
according to spark test result.
Install the spark plugs on original cylinders.
Go to the next step.
Replace the PCV valve.
Go to the next step.
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-
3.7] .)
High:
Replace the fuel pump unit.
(See FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.7] .)
Inspect the fuel injector.