If CKP sensor and wiring harness are normal,
go to the next step.
16
Visually inspect the CKP sensor and
teeth of crankshaft pulley.
Are CKP sensor and teeth of crankshaft
pulley normal?
Yes
Go to the next step.
No
Replace the malfunctioning part.
17
Inspect the ignition coil related wiring
harness condition (intermittent open or
short circuit) for all cylinders. Are
wiring harness conditions normal?
Yes
Go to the next step.
No
Repair the wiring harnesses.
18
Perform the spark test.
(See
ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.7]
.)
Is strong blue spark visible at each
cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part
according to spark test result.
19
Inspect the spark plug conditions.
Is spark plug wet, covered with carbon
or grayish white?
Yes
Spark plug is wet or covered with 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-3.7]
.)
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-
3.7]
.)
High:
Replace the fuel pump unit.
(See
FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.7]
.)
Visually inspect the fuel injector O-ring
and fuel line for fuel leakage.
Yes
Go to the next step.
Inspect the fuel injector.
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:10:05 AM
Page 39
© 2005 Mitchell Repair Information Company, LLC.
