NO.14 POOR FUEL ECONOMY [MZI-3.5]
DESCRIPTION AND POSSIBLE CAUSES
3.5]
.)
High:
Replace the fuel pump unit.
(see
FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.5]
.)
6
Inspect the knock sensor.
Is the knock sensor normal?
Yes
Inspect ignition timing.
No
Replace the knock sensor.
7
z
Verify test results.
{
If normal, return to diagnostic index to service any additional symptoms.
(See
ENGINE SYMPTOM TROUBLESHOOTING [MZI-3.5]
.)
{
If malfunction remains, inspect related Service Bulletins and/or On-line Repair
Information and perform repair or diagnosis.
z
If vehicle is repaired, troubleshooting completed.
z
If vehicle is not repaired or additional diagnostic information is not
available, replace the PCM.
(see
PCM REMOVAL/INSTALLATION [MZI-3.5]
.)
14
POOR FUEL ECONOMY
DESCRIPTION
Fuel economy is unsatisfactory.
z
Contaminated air cleaner element
z
Engine cooling system malfunction
z
Improper ATF level
z
Weak spark
z
Poor fuel quality
z
Erratic or no signal from CMP sensor
z
Improper variable valve timing control system operation
z
Improper coolant level
z
Inadequate fuel pressure
z
Spark plug malfunction
z
PCV valve malfunction
z
Brake dragging
z
Improper valve timing due to jumping out of timing chain
z
Contaminated MAF sensor
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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