NO.14 POOR FUEL ECONOMY [MZI-3.7]
NO.14 POOR FUEL ECONOMY (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
Information and perform repair or diagnosis.
z
If vehicle is repaired, troubleshooting completed.
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If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.
(See
PCM REMOVAL/INSTALLATION [MZI-3.7]
.)
14
POOR FUEL ECONOMY
DESCRIPTION
Fuel economy is unsatisfactory.
POSSIBLE
CAUSE
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Contaminated air cleaner element
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Engine cooling system malfunction
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Improper ATF level
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Weak spark
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Poor fuel quality
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Erratic or no signal from CMP sensor
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Improper variable valve timing control system operation
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Improper coolant level
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Inadequate fuel pressure
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Spark plug malfunction
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PCV valve malfunction
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Brake dragging
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Improper valve timing due to jumping out of timing chain
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Contaminated MAF sensor
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Improper engine compression
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Exhaust system clogging
WARNING:
The following troubleshooting flow chart contains fuel system diagnosis and
repair procedures. Read following warnings before servicing fuel system:
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Fuel vapor is hazardous. It can easily ignite, causing serious injury
and damage. Always keep sparks and flames away from fuel.
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Fuel line spills and leakage are dangerous. Fuel can ignite and cause
serious injuries or death and damage. Fuel can also irritate skin and
eyes. To prevent this, always complete "BEFORE SERVICE
PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this
manual.
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
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© 2005 Mitchell Repair Information Company, LLC.
