Is the spark plug normal?
4
Inspect compression pressure at
suspected malfunctioning
cylinder.
Is compression pressure correct?
(See
COMPRESSION
INSPECTION [MZI-3.7]
.)
Yes
Go to the next step.
No
Repair or replace the malfunctioning part.
5
Install all spark plugs.
Perform the spark test at suspected
malfunctioning cylinder.
Is strong blue spark visible?
(Compare with normal cylinder.)
Yes
Go to the next step.
No
Repair or replace the malfunctioning part.
6
Install the fuel pressure gauge
between fuel filter and fuel
distributor.
Short check connector terminal
F/P to body GND using a jumper
wiring.
Turn the ignition switch to the ON
position (Engine off).
Is the fuel line pressure correct
with the ignition switch at ON?
(See
FUEL LINE PRESSURE
INSPECTION [MZI-3.7]
.)
Yes
Inspect fuel injector for the following:
z
Open or short circuit in injector
z
Leakage
z
Injection volume
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]
.)
7
Inspect the spark plug for the
following.
z
Heat range
z
Air gap
Is the spark plug normal?
Yes
Go to the next step.
No
Replace the spark plug.
(See
SPARK PLUG
REMOVAL/INSTALLATION [MZI-3.7]
.)
8
Remove the suspected fuel
injector.
Inspect the following:
z
Resistance
z
Fuel injection volume
(See
FUEL INJECTOR
Yes
Inspect for open circuit in wiring harness between
fuel injector connector terminal A and PCM at the
following terminals:
z
For No.1 cylinder: 2BJ
z
For No.2 cylinder: 2BM
z
For No.3 cylinder: 2BF
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:10:06 AM
Page 93
© 2005 Mitchell Repair Information Company, LLC.
