NO.7 SLOW RETURN TO IDLE [MZI-3.7]
NO.7 SLOW RETURN TO IDLE (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
23
Service if necessary.
Is the fuel line pressure held after the
ignition switch is turned off?
(See
FUEL LINE PRESSURE
INSPECTION [MZI-3.7]
.)
No
If the fuel injector is normal, replace the fuel
pump unit.
(See
FUEL PUMP UNIT
REMOVAL/INSTALLATION [MZI-
3.7]
.)
24
Disconnect the vacuum hose between
the purge solenoid valve and the intake
manifold from purge solenoid valve
side.
Plug opening end of vacuum hose.
Start the engine.
Is starting condition improved?
Yes
Inspect if the purge solenoid valve is stuck
open mechanically.
Inspect the evaporative emission control
system.
No
Go to the next step.
25
Is air leakage felt or heard at intake-air
system components while racing engine
to higher speed?
Yes
Repair or replace the malfunctioning part.
No
Go to the next step.
26
Inspect the variable valve timing control
system operation.
(See
ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.7]
.)
Does variable valve timing control
function properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part.
27 Is the engine compression correct?
Yes
Inspect the valve timing.
No
Inspect for causes.
28
z
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
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-3.7]
.)
7
SLOW RETURN TO IDLE
DESCRIPTION
Engine takes more time than normal to return to idle speed.
z
CHT sensor malfunction
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
Page 40
© 2005 Mitchell Repair Information Company, LLC.
