Mazda CX-9 Grand Touring 2009 Manual page 1384

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Is the spark plug normal?
Inspect compression pressure at
suspected malfunctioning
cylinder.
4
Is compression pressure correct?
(See COMPRESSION
INSPECTION [MZI-3.7] .)
Install all spark plugs.
Perform the spark test at suspected
5 malfunctioning cylinder.
Is strong blue spark visible?
(Compare with normal cylinder.)
Install the fuel pressure gauge
between fuel filter and fuel
distributor.
Short check connector terminal
F/P to body GND using a jumper
wiring.
6
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] .)
Inspect the spark plug for the
following.
Heat range
7
Air gap
Is the spark plug normal?
Remove the suspected fuel
injector.
Inspect the following:
8
Resistance
Fuel injection volume
(See FUEL INJECTOR
2008 Mazda CX-9 Grand Touring
Yes Go to the next step.
No Repair or replace the malfunctioning part.
Yes Go to the next step.
No Repair or replace the malfunctioning part.
Inspect fuel injector for the following:
Open or short circuit in injector
Yes
Leakage
Injection volume
Inspect the fuel pump relay and fuel pump circuit.
If there is no malfunction, replace the fuel pump
No
REMOVAL/INSTALLATION [MZI-3.7] .)
REMOVAL/INSTALLATION [MZI-3.7] .)
Yes Go to the next step.
No
REMOVAL/INSTALLATION [MZI-3.7] .)
Inspect for open circuit in wiring harness between
fuel injector connector terminal A and PCM at the
following terminals:
Yes
For No.1 cylinder: 2BJ
For No.2 cylinder: 2BM
For No.3 cylinder: 2BF
Zero or low:
Inspect the fuel line for clogging.
unit.
(See FUEL PUMP UNIT
High:
Replace the fuel pump unit.
(See FUEL PUMP UNIT
Replace the spark plug.
(See SPARK PLUG