10
Inspect the spark plug condition.
Is the 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.
11
Perform the electronic throttle control
system operation inspection.
(See
ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.5]
.)
Does the electronic throttle control
system function properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning
part according to electronic throttle
control system operation inspection
results.
12
Install fuel pressure gauge between
fuel pipe and fuel distributor.
Start the engine and run it at idle.
Measure fuel line pressure during idle.
Is fuel line pressure correct during
idle?
(see
FUEL LINE PRESSURE
INSPECTION [MZI-3.5]
.)
Yes
Go to the next step.
No
Low:
Inspect the fuel line for clogging.
If there is no malfunction, replace 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]
.)
13
Visually inspect for fuel leakage at fuel
injector, O-ring, and fuel line.
Service if necessary.
Does fuel line pressure hold after
ignition switch is turned off?
(see
FUEL LINE PRESSURE
INSPECTION [MZI-3.5]
.)
Yes
Go to the next step.
No
Inspect fuel injector.
If fuel injector is normal, replace fuel
pump unit.
(see
FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.5]
.)
14
Connect the M-MDS to the DLC-2.
Start the engine and idle it.
Access LONG FT1 PID, LONG FT2
PID.
Measure LONG FT1 PID, LONG FT2
PID at idle.
Is PID value normal?
Yes
Go to the next step.
No
LONG FT1 PID, LONG FT2 PID is out
of specification.
Less than specification (too rich):
z
Inspect EVAP control system.
Greater than specification (too lean):
z
Inspect for air leakage at intake-
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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