NO.4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANK[AJ (3.0L Duratec)]
id0103a7804600
4
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Hard start/long crank/erratic start/erratic crank
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DESCRIPTION
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• The starter cranks engine at normal speed but the engine requires excessive cranking time before starting.
• The battery is in normal condition.
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POSSIBLE CAUSE
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• Spark leakage from high-tension leads
• Vacuum leakage
• Poor fuel quality
• Starting system malfunction
• Spark plug malfunction
• Air leakage from intake-air system
• Erratic signal from CKP sensor
• Erratic signal from CMP sensor
• Air cleaner restriction
• IAC solenoid valve malfunction
• PCV valve malfunction
• Inadequate fuel pressure
• Purge solenoid valve malfunction
• MAF sensor contamination
• Restriction in exhaust system
• EGR valve malfunction
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Diagnostic procedure
STEP |
INSPECTION |
RESULTS |
ACTION |
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1
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• Inspect for the following:
• Are all items normal?
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Yes
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Go to the next step.
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No
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Service if necessary.
Repeat Step 1.
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2
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• Connect the M-MDS to the DLC–2.
• Turn the ignition to the ON position (Engine off).
• Retrieve any DTCs.
• Is “PASSED” displayed?
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Yes
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No DTC is displayed:
• Go to the next step.
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No
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DTC is displayed:
• Go to the appropriate DTC test.
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3
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• Is the engine overheating?
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Yes
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Go to flowchart “No.17 Cooling system concerns—Overheating”.
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No
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Go to the next step.
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4
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• Inspect for cracks on the high-tension leads
• Is there any crack on the high-tension leads?
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Yes
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Repair suspected high-tension lead.
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No
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Go to the next step.
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5
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• Inspect the spark plug conditions.
• Is the spark plug wet, covered with carbon or grayish white?
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Yes
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Spark plug is wet or covered with carbon:
• Inspect for fuel leakage from fuel injector.
Spark plug is grayish white:
• Inspect for clogged fuel injector.
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No
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Install spark plugs on original cylinders.
Go to the next step.
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6
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• Visually inspect CKP sensor and teeth of crankshaft pulley.
• Are CKP sensor and teeth of crankshaft pulley normal?
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Yes
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Go to the next step.
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No
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Replace malfunctioning part.
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7
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• Remove and shake PCV valve.
• Does PCV valve rattle?
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Yes
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Go to the next step.
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No
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Replace the PCV valve.
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8
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• Install fuel pressure gauge to fuel line.
• Connect the M-MDS to DLC-2.
• Turn the fuel pump on using FP PID in output state control of datalogger function.
• Is the fuel line pressure connect?
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Yes
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Go to the next step.
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No
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Zero or low:
Inspect the fuel pump, fuel pump stop switch and fuel pump relay related circuit.
Inspect for clogged fuel line.
• If normal, replace the fuel pump unit.
High:
Replace the fuel pump unit.
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9
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• Is the fuel line pressure held after FP PID is turned to OFF?
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Yes
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Go to the next step.
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No
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Inspect the fuel injector.
• If the fuel injector is normal, replace the fuel pump unit.
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10
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• Disconnect the vacuum hose from purge solenoid valve and plug opening end of vacuum hose.
• Attempt to start engine.
• Is the starting condition improved?
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Yes
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Inspect if the purge solenoid valve sticks open.
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No
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Go to the next step.
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11
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• Inspect the MAF sensor for contamination.
• Is there any contamination?
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Yes
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Replace the MAF sensor.
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No
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Go to the next step.
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12
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• Visually inspect the exhaust system part.
• Is there any deformed exhaust system part?
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Yes
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Replace the suspected part.
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No
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Go to the next step.
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13
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• Inspect engine condition while tapping EGR valve housing.
• Does the engine condition improve?
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Yes
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Replace the EGR valve.
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No
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Go to the next step.
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14
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• Inspect the starting system.
• Is the starting system normal?
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Yes
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Inspect for loose connectors or poor terminal contact.
• If normal, remove the EGR valve and visually inspect for mechanically stuck EGR valve.
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No
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Repair or replace the components if necessary.
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15
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• Verify the test results.
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