Downloaded from www.Manualslib.com manuals search engine Hard Start / Long Crank / Erratic Start / Erratic Crank
The following conditions apply to this symptom:
•The engine cranks for an extended period of time.
• The engine starts hard during a long cranking time.
1.PRELIMINARY CHECKS
• Confirm that the correct starting procedure was used by the customer before proceeding with diagnosis.
• Carry out the following preliminary checks:
Vacuum leaks
Fuel quality (concerns such as correct octane, contamination, winter/summer blend)
Intake air system (tubes)
Air cleaner (restrictions)
Battery condition and starter current draw.
Are all checks OK?
Ye s>>Go to the next step.
No
>>Repair as necessary.
Verify the symptom no longer exists.
2.CHECK ECM DTC
• With scan tool X-431, select view DTC and data stream in ECM.
Are there any DTCs present?
Ye s>>See the Diagnostic Trouble Code (DTC) List.
Go to the specific diagnostic test to troubleshoot the DTC.
No
>>Go to the next step.
3.CHECK SECONDARY IGNITION SYSTEM
• Perform the following to test the secondary ignition system:
Disconnect the injector fuse.
Remove any of the 4 spark plugs.
Connect the spark plug to spark plug wire.
Ground the spark plug on the cylinder block.
Crank the engine to test the secondary ignition system with the spark plugs removed.
Is a strong blue spark visible at each spark plug while cranking the engine?
Ye s>>Go to the next step.
No
>>Check Camshaft Position (CMP) sensor signal at ECM.
If CMP sensor is OK, check the following:
Crankshaft Position (CKP) sensor malfunction
Faulty spark plug wires
Faulty spark plugs
ELECTRONIC ENGINE CONTROLS - 2.4L ENGINE SYMPTOM DIAGNOSIS
03
03–549Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine 8.CHECK EVAPORATIVE EMISSIONS (EVAP) SYSTEM
• Disconnect the canister control valve (1) hose.
• Place a stiff piece of paper over the hose end and
start the engine.
Does vacuum hold the paper?
Ye s>>Check for a vacuum leak in EVAP system
(refer to EVAP system) and refer to EVAP control cir-
cuit relative DTC.
No
>>Go to the next step.
9.CHECK INTAKE AIR SYSTEM
• Check for MAP/MAF sensor.
Is there any contamination?
Ye s>>Install a new MAF/IAT or MAP/IAT sensor.
No
>>See Diagnostic Help for additional information.
ELECTRONIC ENGINE CONTROLS - 2.4L ENGINE SYMPTOM DIAGNOSIS
VISMD030007
03
03–551Chery Automobile Co., Ltd.