No.7 Slow Return To Idle - Mazda CX-7 2007 Workshop Manual

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
STEP INSPECTION
36 Measure the compression pressure for each
cylinder.
(See01-10-9 COMPRESSION INSPECTION[L3
WITH TC].)
Are the compression pressures within the
specification?
37 Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the
repair or diagnosis.
— If the vehicle is repaired, troubleshooting is completed.
— If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later
calibration is available. Retest.
End Of Sie
NO.7 SLOW RETURN TO IDLE[L3 WITH TC]
7 SLOW RETURN TO IDLE
• Engine takes more time than normal to return to idle speed.
DESCRIPTION
• Engine speed continues at fast idle after warm-up
• ECT sensor or related circuit malfunction
• Thermostat is stuck open
• Fuel injection timing is incorrect
• Erratic signal from CKP sensor
• Erratic signal from CMP sensor
• Accelerator position sensor or related circuit malfunction
• Air suction in intake-air system
• MAF sensor or related circuit malfunction
• Fuel pressure sensor or related circuit malfunction
• Excessive fuel pressure
• Relief valve malfunction (built-in delivery pipe)
• Fuel injector malfunction
• Cooling fan control system malfunction
• Improper load signal input
• Injector driver module or related circuit malfunction
Warning
POSSIBLE CAUSE
The following troubleshooting flow chart contains the fuel system diagnosis and repair
procedures. Read the following warnings before performing the fuel system services:
• Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always
• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or
Caution
• Disconnecting/connecting the quick release connector without cleaning it may possibly
Diagnostic procedure
STEP INSPECTION
1 Inspect air suction in intake-air system
components while racing engine to higher
speed.
Is any air suction?
01-03–32
keep sparks and flames away from fuel.
death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete
"BEFORE REPAIR ROCEDURE" and "AFTER REPAIR PROCEDURE" described in this
manual.
(See01-14-4 BEFORE REPAIR PROCEDURE[L3 WITH TC].)
(See01-14-4 AFTER REPAIR PROCEDURE[L3 WITH TC].)
cause damage to the fuel pipe and quick release connector. Always clean the quick release
connector joint area before disconnecting/connecting, and make sure that it is free of
foreign material.
RESULTS
Yes Replace the injector driver module.
If the problem remains, overhaul the engine.
No Inspect for the following:
• Damaged valve seat
• Worn valve stem and valve guide
• Worn or stuck piston ring
• Worn piston, piston ring or cylinder
• Improper valve timing
Service if necessary.
RESULTS
Yes Repair or replace as necessary.
No Go to the next step.
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