NO.4 ENGINE STALLS-AFTER START/AT IDLE [F2]

id010394912400

4

ENGINE STALLS—AFTER START/AT IDLE
DESCRIPTION
•  Engine stop unexpectedly at idle and/or after start.
POSSIBLE CAUSE
•  Improper A/C system operation
•  Air leakage from intake-air system parts
•  Purge solenoid valve malfunction
•  Improper IAC valve operation
•  No signal from the CKP sensor due to sensor, related wire or wrong installation
•  Vacuum leakage
•  Low engine compression
•  Spark leakage from high-tension leads
•  Poor fuel quality
•  PCV valve malfunction
•  Air cleaner restriction
•  Restriction in exhaust system
•  Electrical connector disconnection
•  Open or short circuit in fuel pump body and related harness
•  No battery power supply to PCM or poor ground
•  Inadequate fuel pressure
•  Fuel pump body mechanical malfunction
•  Fuel leakage from fuel injector
•  Fuel injector clogging
•  Pressure regulator control (PRC) system malfunction
Warning
•  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 keep sparks and flames away from fuel.
―  Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual.
Caution
•  If there is foreign material on the connecting area of the quick release connector, it might damage the connector or fuel pipe. To prevent this, disconnect the connector and clean the connecting area before connecting.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Verify 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 (e.g. IAC valve)
•  Ignition wiring
•  Fuel quality (e.g. proper octane, contamination, winter/summer blend)
•  Electrical connections.
•  Smooth operation of throttle valve
Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 1.
2
Turn the ignition switch to the ON position.
Disconnect TP sensor connector.
Measure voltage at TP sensor connector VREF terminal with ignition switch on.
Voltage
4.5—5.5 V
Is voltage normal?
Yes
Go to the next step.
No
Go to symptom troubleshooting “No.27 Constant voltage”.
3
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?
Yes
DTC is displayed:
•  Go to appropriate the DTC inspection.
No
No DTC is displayed:
•  Inspect instrument cluster operation.
4
Attempt to short engine at part throttle.
Does engine run smoothly at part throttle?
Yes
Inspect IAC valve and wiring harness.
No
Go to the next step.
5
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?
Yes
DTC is displayed:
•  Go to appropriate the DTC inspection.
No
No DTC is displayed:
•  Inspect instrument cluster operation.
6
Visually inspect CMP sensor.
Is CMP sensor normal?
Yes
Go to the next step.
No
Replace malfunctioning parts.
7
Inspect for cracks on high-tension leads.
Are there any cracks on high-tension leads?
Yes
Repair suspected high-tension lead.
No
Go to the next step.
8
Is strong blue spark visible at each disconnected high-tension lead while cranking engine?
Yes
Go to the next step.
If symptom occurs with A/C on, go to Step 14.
No
Inspect for following:
•  Open or short circuit in ignition coil
•  Open circuit in high-tension leads
•  Open circuit between igniter connector ground terminal and body ground
•  Open circuit between ignition switch and ignition coil
•  Open circuit between ignition coil and condenser
•  Open circuit between condenser and igniter
•  Open circuit between ignition coil and igniter
•  Open circuit between ignition and PCM terminal 2F
9
Inspect spark plug condition.
Is spark plug wet, covered with carbon, or grayish white?
Yes
Spark plug is wet or covered with carbon:
Inspect for fuel leakage from injector.
Spark plug is grayish white:
Inspect for clogged fuel injector.
No
Install spark plugs on original cylinders.
Go to the next step.
10
Remove and shake PCV valve.
Does PCV valve rattle?
Yes
Go to next step.
No
Replace PCV valve.
11
Is there any restriction in the exhaust system?
Yes
Inspect exhaust system.
No
Go to the next step.
12
Install fuel pressure gauge between fuel main pipe and fuel distributor.
Connect jumper wire between F/P terminal at DLC and ground.
Turn the ignition switch to the ON position.
Is fuel line pressure correct with ignition switch on?
(See FUEL PUMP UNIT INSPECTION [F2].)
Yes
Go to the next step.
No
Zero or low:
Inspect the fuel pump circuit.
Inspect for open the furl pump relief valve.
Inspect for the fuel leakage inside pressure regulator.
Inspect for clogged main fuel line.
Inspect PRC solenoid valve, related vacuum hose and related harnesses.
High:
Inspect pressure regulator for high pressure cause.
Inspect for clogged fuel return line.
13
Visually inspect for fuel leakage at fuel injector, O-ring, and fuel line. Service as necessary.
Does fuel line pressure hold after the ignition switch is turned off?
(See FUEL PUMP UNIT INSPECTION [F2].)
Yes
Go to the next step.
No
Inspect pressure regulator diaphragm condition.
If condition is normal, inspect the fuel injector.
If condition is not normal, replace the pressure regulator.
14
Note
•  The following test is for stall concerns with A/C on. If other symptoms exist, go to next step.
Connect pressure gauges to A/C low and high pressure side lines.
Turn A/C on and measure low side and high side pressure.
Is pressure within specifications?
Yes
Go to the next step.
No
If A/C is always on, go to symptom troubleshooting “No.23 A/C compressor runs continuously”.
For other symptoms, inspect following:
•  Refrigerant charging amount
15
Disconnect vacuum hose between purge solenoid valve and dynamic chamber from purge solenoid side. Plug opening end of vacuum hose.
Start engine.
Is engine stall now eliminated?
Yes
Inspect if purge solenoid valve sticks to open.
Inspect evaporative emission control system.
No
Go to the next step.
16
Is air leakage felt or heard at intake-air system components while racing engine to higher speed?
Yes
Repair or replace.
No
Go to the next step.
17
Is engine compression correct?
Yes
Inspect valve timing.
No
Inspect for cause.
18
•  Verify test results.
―  If normal, return to diagnostic index to service any additional symptoms.
―  If malfunction remains, inspect related Service Information and perform repair or diagnosis.
•  If vehicle is repaired, troubleshooting completed.
•  If vehicle is not repaired or additional diagnostic information is not available, replace the PCM.