NO.5 ENGINE STALLS-AFTER START/AT IDLE [MZI-3.7]
id0103d2801100
5 |
ENGINE STALLS—AFTER START/AT IDLE |
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DESCRIPTION
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• Engine stops unexpectedly.
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POSSIBLE CAUSE
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• Vacuum leakage
• Air leakage from intake-air system parts
• Air cleaner restriction
• Poor fuel quality
• Electrical connector disconnection
• Throttle valve restriction or clogged
• PCM DTC is stored.
• No battery power supply to PCM or poor ground
• Erratic signal to PCM
• Improper operation of drive-by-wire control system
• Restriction in exhaust system
• No signal from CKP sensor due to sensor, related wire or wrong installation
• Ignition coil or related circuit malfunction
• Spark plug malfunction
• Fuel leakage from fuel injector
• Fuel injector clogging
• Inadequate fuel pressure
• Fuel leakage from fuel system
• PCV valve malfunction
• A/C system operation is improper.
• Purge solenoid valve malfunction
• Air leakage from intake air system when the engine runs high speed
• Improper operation variable valve timing control system
• Low engine compression
• Improper valve timing
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Diagnostic procedure
STEP |
INSPECTION |
RESULTS |
ACTION |
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1
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Verify the following:
• Vacuum connection
• Air cleaner element
• No air leakage from intake-air system
• No restriction of intake-air system
• Proper sealing of intake manifold and components attached to intake manifold
• Ignition wiring
• Fuel quality: proper octane, contamination, winter/summer blend
• Electrical connections
• Smooth operation of throttle valve
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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Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 1.
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2
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Turn the ignition switch to the ON position (Engine off).
Retrieve any PCM DTCs using the M-MDS.
Are there any DTCs displayed?
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Yes
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DTC is displayed:
• Go to the appropriate DTC inspection.
Communication error message is displayed:
Inspect for the following:
Repair or replace the malfunctioning part according to the inspection results.
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No
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No DTC is displayed:
• Go to the next step.
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3
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Access the following PCM PIDs using the M-MDS:
• APP1
• APP2
• APP3 (PCM connector (2 types))
Crank the engine with the accelerator pedal released.
Are the PIDs indicating that the accelerator pedal is in the released position?
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Yes
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Go to the next step.
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No
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Inspect for the following:
• APP sensor
• Wiring harnesses and connectors for following:
Repair or replace the malfunctioning part according to the inspection results.
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4
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Access the PCM PIDs TP1, TP2 using the M-MDS.
Crank the engine with the accelerator pedal released.
Are the TP1, TP2 PID indicates the closed throttle position?
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Yes
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Go to the next step.
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No
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Inspect for the following:
• TP sensor
• Wiring harnesses and connectors for following:
Repair or replace the malfunctioning part according to the inspection results.
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5
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Attempt to start the engine at part throttle.
Does the engine run smoothly at part throttle?
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Yes
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Inspect the drive-by-wire control system operation.
Repair or replace the malfunctioning part according to the inspection results.
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No
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Go to the next step.
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6
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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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Repair or replace the malfunctioning part according to the inspection results.
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No
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Go to the next step.
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7
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Access the PCM PID RPM using the M-MDS.
Is the RPM PID indicating the engine speed during the engine cranking?
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Yes
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Go to the next step.
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No
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Inspect for the following:
• Open or short circuit in CKP sensor
• Open or short circuit in CKP sensor wiring harnesses
• PCM connector (2 types):
• PCM connector (3 types):
Repair or replace the malfunctioning part according to the inspection results.
• If CKP sensor and wiring harness are normal, go to the next step.
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8
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Inspect the CKP sensor.
Is the CKP sensor normal?
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Yes
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Go to the next step.
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No
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Repair or replace the malfunctioning part according to the inspection results.
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9
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Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders.
Are wiring harness conditions normal?
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Yes
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Go to the next step.
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No
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Repair or replace suspected wiring harness and connector.
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10
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Perform the spark test.
Is strong blue spark visible at each cylinder?
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Yes
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Go to the next step.
• If symptoms occurs with the A/C on, go to Step 15.
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No
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Repair or replace the malfunctioning part according to the inspection results.
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11
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Verify the spark plug conditions when the spark plug removed in Step 10.
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 the fuel injector for clogging.
Repair or replace the malfunctioning part according to the inspection results.
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No
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Install the spark plugs on original cylinders.
Go to the next step.
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12
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Inspect the fuel line pressure.
Is the fuel line pressure correct?
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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 following:
• If there is no malfunction, replace the fuel pump unit. (Fuel pump or pressure regulator malfunction)
High:
• Replace the fuel pump unit. (Pressure regulator malfunction)
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13
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Visually inspect for fuel leakage at fuel injector, O-ring, and fuel line.
Is there any fuel leakage?
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Yes
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Repair or replace the malfunctioning part according to the inspection results.
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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 PCV valve with it installed.
Is the PCV valve 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 the PCV valve.
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15
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Connect the pressure gauges to A/C low and high pressure side lines.
Turn the A/C on and measure low side and high side pressures.
(See REFRIGERANT PRESSURE CHECK.)
Are pressures within specifications?
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Yes
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Go to the next step.
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No
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If the A/C is always on:
• Go to the symptom troubleshooting “NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY”.
For other symptoms:
• Inspect the following:
• Repair or replace the malfunctioning part according to the inspection results.
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16
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Disconnect the vacuum hose between purge solenoid valve and intake manifold from purge solenoid side.
Plug opening end of vacuum hose.
Start the engine.
Is the engine stall now eliminated?
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Yes
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Inspect the following:
• If purge solenoid valve is stuck open.
• EVAP control system
Repair or replace the malfunctioning part according to the inspection results.
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No
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Go to the next step.
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17
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Is air leakage felt or heard at intake-air system components while racing the engine to higher speed?
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Yes
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Repair or replace the malfunctioning part according to the inspection results.
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No
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Go to the next step.
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18
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Inspect the variable valve timing control system operation.
Does the variable valve timing control function properly?
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Yes
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Go to the next step.
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No
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Repair or replace the malfunctioning part according to the inspection results.
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19
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Is the engine compression correct?
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Yes
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Inspect the valve timing.
Repair or replace the malfunctioning part according to the inspection results.
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No
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Inspect for cause.
Repair or replace the malfunctioning part according to the inspection results.
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20
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• Verify test results.
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