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2008 - MX-5 - Engine

NO.5 ENGINE STALLS-AFTER START/AT IDLE [LF]



5

ENGINE STALLS—AFTER START/AT IDLE

DESCRIPTION

  • Engine stops unexpectedly.

POSSIBLE CAUSE

  • A/C system operation is improper

  • Air leakage from intake-air system parts

  • Purge solenoid valve malfunction

  • Improper operation of electronic throttle control system

  • EGR valve malfunction

  • No signal from CKP sensor due to sensor, related wire or wrong installation

  • Vacuum leakage

  • Engine overheating

  • Low engine compression

  • Erratic signal to ignition coil

  • 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 wiring harness

  • No battery power supply to PCM or poor GND

  • Inadequate fuel pressure

  • Fuel pump body mechanical malfunction

  • Fuel leakage from fuel injector

  • Fuel injector clogging

  • Ignition coil malfunction

  • Improper air/fuel mixture ratio control

  • Improper valve timing

  • Improper operation variable valve timing control system

  • Immobilizer system and/or circuit malfunction

  • Immobilizer system operating property. (Ignition key is not registered.)

  • Pressure regulator malfunction (built-in fuel pump unit)

WARNING:

The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:
  • 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 “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual.

    (See BEFORE SERVICE PRECAUTION [LF].)

    (See AFTER SERVICE PRECAUTION [LF].)

CAUTION:

  • Disconnecting/connecting quick release connector without cleaning it may cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.


Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1

Connect the M-MDS to the DLC-2.

Do the following conditions appear?

  • The engine is not completely started.

  • DTC P1260 is displayed.

Yes

Both conditions appear:

Go to Step 3.

No

Either or other condition appears:

Go to the next step.

2

Does the engine stall after approx. 2 s since the engine is started?

Yes

Go to the next step.

No

Immobilizer system is normal.

Go to Step 8.

3

Is coil connector securely connected to coil?

Yes

Go to the next step.

No

Connect the coil connector securely.

Return to Step 2.

4

Does the security light flush?

Yes

Go to the next step.

No

Inspect and repair or replace the following:

  • Wiring harnesses and connectors from keyless control module terminal 3F and instrument cluster terminal 2F

  • Instrument cluster

(See INSTRUMENT CLUSTER INSPECTION.)

5

Connect the M-MDS to the DLC-2 and retrieve DTC for PCM, instrument cluster and keyless control module (with advanced keyless entry system).

Are any of the following DTCs displayed?

    DTC
  • PCM: B1342, U0073, U0155

  • Instrument cluster: B1213, B1600, B1601, B1602, B1681, B2103, 2139, B2431, U0110, U0214

  • Keyless control module (with advanced keyless entry system): B1681, B2103, B1213

Yes

Go to the appropriate DTC inspection.

(See DTC TABLE [LF].)

No

Go to the next step.

6

Inspect for the following wiring harnesses and connectors:

    With advanced keyless entry system
  • Between coil terminal A and keyless control module terminal 3Y

  • Between coil terminal B and keyless control module terminal 3AA

  • Between keyless control module terminal 4A and instrument cluster terminal 2Q

  • Between keyless control module terminal 4C and instrument cluster terminal 2S

    Without advanced keyless entry system
  • Between coil terminal A and instrument cluster terminal 2S

  • Between coil terminal B and instrument cluster terminal 2Q

Is there any malfunction?

Yes

Repair or replace the suspected wiring harness and connector.

No

Go to the next step.

7

Inspect for the following wiring harnesses and connectors:

  • Between PCM terminal 1AM and instrument cluster terminal 1J

  • Between PCM terminal 1AI and instrument cluster terminal 1L

Is there any malfunction?

Yes

Repair or replace the suspected wiring harness and connector.

No

Go to the next step.

8

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:

    EGR valve

  • Ignition wiring

  • Fuel quality: 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 8.

9

Connect the M-MDS to the DLC-2.

Access the APP1 and APP2 PIDs. Crank the engine with accelerator pedal released.

Are the APP1 and APP2 PIDs indicating that the accelerator pedal is in the released position?

Yes

Go to the next step.

No

Inspect for the following:

  • APP sensor

  • Wiring harnesses and connectors for following:

    • PCM terminal 1AJ—APP sensor terminal A

    • PCM terminal 1AV—APP sensor terminal B

    • PCM terminal 1AP—APP sensor terminal C

    • PCM terminal 1AL—APP sensor terminal D

    • PCM terminal 1AS—APP sensor terminal E

    • PCM terminal 1AO—APP sensor terminal F

10

Connect the M-MDS to the DLC-2.

Access the TP PID. Crank the engine with accelerator pedal released.

Are the TP PID indicates the closed throttle position?

Yes

Go to the next step.

No

Inspect for the following:

  • TP sensor

  • Wiring harnesses and connectors for following:

    • PCM terminal 2AK—TP sensor terminal F

    • PCM terminal 2AO—TP sensor terminal E

    • PCM terminal 2AP—TP sensor terminal C

    • PCM terminal 2AL—TP sensor terminal D

11

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 DTC inspection.

(See DTC TABLE [LF].)

Communication error message is displayed:

Inspect for the following:

  • Open circuit in wiring harness between main relay and PCM terminal 1AW or 1BE

  • Open main relay GND circuit

  • Main relay is stuck open.

  • Open or short circuit in wiring harness between DLC and PCM terminals 1AM or 1AI

  • Open or poor GND circuit (PCM terminal 1AZ, 1BB, 1BD, 1BH)

  • Poor connection of vehicle body GND

No

No DTC is displayed:

Go to the next step.

12

Attempt to start engine at part throttle.

Does engine run smoothly at part throttle?

Yes

Inspect electronic throttle control system operation.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF].)

No

Go to the next step.

13

Connect the M-MDS to the DLC-2.

Access RPM PID.

Is RPM PID indicating engine speed during engine cranking?

Yes

Go to the next step.

No

Inspect for the following:

  • Open or short circuit in CKP sensor

  • Open or short circuit in wiring harness between CKP sensor terminal A and PCM terminal 2AB

  • Open or short circuit in wiring harness between CKP sensor terminal B and PCM terminal 2W

  • Open or short circuit in wiring harness between CKP sensor terminal C and PCM terminal 2AQ

  • Open or short circuit in CKP sensor wiring harnesses

If CKP sensor and wiring harness are normal, go to the next step.

14

Visually inspect CKP sensor and teeth of crankshaft pulley.

Are CKP sensor and teeth of crankshaft pulley normal?

Yes

Go to the next step.

No

Replace the malfunctioning part.

15

Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are wiring harness conditions normal?

Yes

Go to the next step.

No

Repair the wiring harnesses.

16

Perform the spark test.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF].)

Is strong blue spark visible at each cylinder?

Yes

Go to the next step.

If symptoms occurs with the A/C on, go to Step 22.

No

Repair or replace the malfunctioning part according to spark test result.

17

Inspect the 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 the fuel injector for clogging.

No

Install spark plugs on original cylinders.

Go to the next step.

18

Remove and shake the PCV valve.

Does the PCV valve rattle?

Yes

Go to the next step.

No

Replace the PCV valve.

19

visually inspect the exhaust system part.

Is there any deformed exhaust system part?

Yes

Replace the suspected part.

No

Go to the next step.

20

Install the fuel pressure gauge between the fuel pipe and the fuel distributor.

Short check connector terminal F/P to body GND using a jumper wiring.

Turn the ignition switch to the ON position.

Is fuel line pressure correct with ignition switch ON?

(See FUEL LINE PRESSURE INSPECTION [LF].)

Yes

Go to the next step.

No

Zero or low:

Inspect the fuel pump relay and fuel pump circuit.

Inspect the fuel line for clogging.

If there is no malfunction, replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF].)

High:

Replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF].)

21

Visually inspect for fuel leakage at fuel injector O-ring and fuel line.

Service if necessary.

Is fuel line pressure held after ignition switch is turned off?

(See FUEL LINE PRESSURE INSPECTION [LF].)

Yes

Go to the next step.

No

Inspect the fuel injector.

If the fuel injector is normal, replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF].)

22

NOTE:

  • The following test is for stall concerns with the A/C on. If other symptoms exist, go to the 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 pressures.

Are pressures within specifications?

(See REFRIGERANT PRESSURE CHECK.)

Yes

Go to the next step.

No

If A/C is always on, go to symptom troubleshooting "No.24 A/C is always on or A/C compressor runs continuously".

(See NO.24 A/C IS ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY [LF].)

For other symptoms, inspect the following:

  • Refrigerant charging amount

  • Condenser fan operation

23

Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from purge solenoid side.

Plug opening end of vacuum hose.

Start the engine.

Is the engine stall now eliminated?

Yes

Inspect if purge solenoid valve is stuck open.

Inspect evaporative emission control system.

No

Go to the next step.

24

Is air leakage felt or heard at intake-air system components while racing the engine to higher speed?

Yes

Repair or replace the malfunctioning part.

No

Go to the next step.

25

Inspect the engine condition while tapping EGR valve housing.

Does the engine condition improve?

Yes

Replace the EGR valve.

No

Go to the next step.

26

Inspect variable valve timing control system operation.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF].)

Does variable valve timing control function properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning parts according to variable valve timing control system operation inspection results.

27

Is the engine compression correct?

Yes

Inspect the valve timing.

No

Inspect for cause.

28

  • Verify test results.

    • If normal, return to diagnostic index to service any additional symptoms.

      (See SYMPTOM DIAGNOSTIC INDEX [LF].)

    • If malfunction remains, inspect related Service Bulletins and/or On-line Repair 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.

        (See PCM REMOVAL/INSTALLATION [LF].)




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