Mazda CX-9 Grand Touring 2009 Manual page 1331

Service if necessary.
Is the fuel line pressure held after the
23 ignition switch is turned off?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)
Disconnect the vacuum hose between
the purge solenoid valve and the intake
manifold from purge solenoid valve
24 side.
Plug opening end of vacuum hose.
Start the engine.
Is starting condition improved?
Is air leakage felt or heard at intake-air
25 system components while racing engine
to higher speed?
Inspect the variable valve timing control
system operation.
(See ENGINE CONTROL SYSTEM
26 OPERATION INSPECTION [MZI-
3.7].)
Does variable valve timing control
function properly?
27 Is the engine compression correct?
Verify test results.
If normal, return to diagnostic index to service any additional symptoms.
(See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].)
If malfunction remains, inspect related Service Bulletins and/or On-line Repair
28
Information and perform repair or diagnosis.
NO.7 SLOW RETURN TO IDLE [MZI-3.7]
NO.7 SLOW RETURN TO IDLE (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
7
DESCRIPTION
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
No
No
No
No
No
If vehicle is repaired, troubleshooting completed.
If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.
(See PCM REMOVAL/INSTALLATION [MZI-3.7] .)
SLOW RETURN TO IDLE
Engine takes more time than normal to return to idle speed.
CHT sensor malfunction
If the fuel injector is normal, replace the fuel
(See FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
Inspect if the purge solenoid valve is stuck
open mechanically.
Yes
Inspect the evaporative emission control
system.
Go to the next step.
Yes Repair or replace the malfunctioning part.
Go to the next step.
Yes Go to the next step.
Repair or replace the malfunctioning part.
Yes Inspect the valve timing.
Inspect for causes.
pump unit.
3.7] .)