Chery Tiggo. Manual — part 209
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?
Yes
>>
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?
Yes
>>
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?
Yes
>>
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
4.
CHECK FUEL SYSTEM PRESSURE
• Release the fuel system pressure (See Fuel Pressure Relief Procedure in Section 04 Fuel Delivery).
• Check fuel system pressure (See Fuel Pressure Test in Section 04 Fuel Delivery).
Is fuel pressure correct?
Yes
>>
Go to the next step.
No
>>
If the fuel pressure is greater than 400 kPa (4.0 bar):
− Replace the fuel pressure regulator.
If the fuel pressure is less than 400 kPa (4.0 bar):
− Check the fuel supply system for restrictions or leaks.
− If no problems, repair or replace fuel filter, pressure regulator or fuel pump assembly.
5.
CHECK EXHAUST SYSTEM
• Check the exhaust system for restrictions.
Is there a restriction in the exhaust system?
Yes
>>
Repair as necessary.
No
>>
Go to the next step.
6.
CHECK ENGINE OVERHEATING
• Is the engine overheating (hot start concern only)?
For hot start concerns, does engine appear to be overheating?
Yes
>>
Repair the engine cooling system.
No
>>
Go to the next step.
7.
CHECK POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM
• Remove the PCV valve and shake it.
Does PCV valve rattle?
Yes
>>
Go to the next step.
No
>>
Replace the PCV valve.
ELECTRONIC ENGINE CONTROLS - 2.4L ENGINE SYMPTOM DIAGNOSIS
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?
Yes
>>
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?
Yes
>>
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
Fast Idle
The following conditions apply to this symptom:
• The engine idles at a higher than recommended speed.
1.
VERIFY ENGINE OPERATES AT NORMAL OPERATING TEMPERATURE
• Check the engine operating temperature.
Does the engine appear to be either overheating or not reaching normal operating temperature?
Yes
>>
Repair the engine cooling system.
No
>>
Go to the next step.
2.
PRELIMINARY CHECKS
• Carry out the following preliminary checks:
− Vacuum leaks
− Throttle plate and linkage
− Intake air tube (leaks)
− Correct sealing of intake manifold and components attached to intake air tube
Are all checks OK?
Yes
>>
Go to the next step.
No
>>
Repair as necessary.
Verify the symptom no longer exists.
3.
CHECK ECM DTC
• Turn the ignition switch on.
• With the scan tool X-431, select view DTC and data stream in ECM.
Are there any DTCs present?
Yes
>>
See the Diagnostic Trouble Code (DTC) List.
Go to the specific diagnostic test to troubleshoot the DTC.
No
>>
See Diagnostic Help for additional information.
ELECTRONIC ENGINE CONTROLS - 2.4L ENGINE SYMPTOM DIAGNOSIS
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