NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [MZR 1.6]

11	ENGINE STALLS/QUITS—ACCELERATION/CRUISE ENGINE RUNS ROUGH—ACCELERATION/CRUISE MISSES—ACCELERATION/CRUISE BUCK/JERK—ACCELERATION/CRUISE/DECELERATION HESITATION/STUMBLE—ACCELERATION SURGES—ACCELERATION/CRUISE
DESCRIPTION	• The engine stops unexpectedly at beginning of acceleration or during acceleration. • The engine stops unexpectedly while cruising. • The engine speed fluctuates during acceleration or cruising. • The engine misses during acceleration or cruising. • The vehicle bucks/jerks during acceleration, cruising, or deceleration. • Momentary pause at beginning of acceleration or during acceleration. • Momentary minor irregularity in engine output.
POSSIBLE CAUSE	• Drive-by-wire control system operates with brake override system • Air cleaner restriction • Electrical connector disconnection • Poor fuel quality • Fuse malfunction • Ignition wiring malfunction • Air leakage from intake-air system • Intake-air system restriction • Improper operation of throttle valve • Vacuum leakage • Continuous memory DTC is stored • Engine overheating • Erratic signal from APP sensor • Erratic signal from CKP sensor • Erratic signal from TP sensor • Intermittent open or short circuit of APP sensor, MAF sensor and TP sensor • ABS or DSC system malfunction (MTX) • CKP sensor and teeth of the crankshaft pulley • Spark plug malfunction • Fuel leakage from fuel injector • Fuel injector clogged • Improper operation of drive-by-wire control system • Restriction in exhaust system • Inadequate fuel pressure • Pressure regulator (built-in fuel pump unit) malfunction • Improper operation of A/C system • Improper operation of air/fuel mixture ratio control • Check valve (two-way) malfunction • Purge solenoid valve malfunction • EVAP control system malfunction • CMP sensor and projections of the camshaft sprocket malfunction • Improper operation of variable valve timing control system • Low engine compression • PCV valve malfunction • Clutch malfunction (MTX) • ATX malfunction (ATX) • Valve timing malfunction • PCM 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. (See BEFORE SERVICE PRECAUTION [MZR 1.6].) (See AFTER SERVICE PRECAUTION [MZR 1.6].) 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.

ENGINE STALLS/QUITS—ACCELERATION/CRUISE

ENGINE RUNS ROUGH—ACCELERATION/CRUISE

MISSES—ACCELERATION/CRUISE

BUCK/JERK—ACCELERATION/CRUISE/DECELERATION

HESITATION/STUMBLE—ACCELERATION

SURGES—ACCELERATION/CRUISE

DESCRIPTION

• The engine stops unexpectedly at beginning of acceleration or during acceleration.

• The engine stops unexpectedly while cruising.

• The engine speed fluctuates during acceleration or cruising.

• The engine misses during acceleration or cruising.

• The vehicle bucks/jerks during acceleration, cruising, or deceleration.

• Momentary pause at beginning of acceleration or during acceleration.

• Momentary minor irregularity in engine output.

POSSIBLE CAUSE

• Drive-by-wire control system operates with brake override system

• Air cleaner restriction

• Electrical connector disconnection

• Poor fuel quality

• Fuse malfunction

• Ignition wiring malfunction

• Air leakage from intake-air system

• Intake-air system restriction

• Improper operation of throttle valve

• Vacuum leakage

• Continuous memory DTC is stored

• Engine overheating

• Erratic signal from APP sensor

• Erratic signal from CKP sensor

• Erratic signal from TP sensor

• Intermittent open or short circuit of APP sensor, MAF sensor and TP sensor

• ABS or DSC system malfunction (MTX)

• CKP sensor and teeth of the crankshaft pulley

• Spark plug malfunction

• Fuel leakage from fuel injector

• Fuel injector clogged

• Improper operation of drive-by-wire control system

• Restriction in exhaust system

• Inadequate fuel pressure

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

• Improper operation of A/C system

• Improper operation of air/fuel mixture ratio control

• Check valve (two-way) malfunction

• Purge solenoid valve malfunction

• EVAP control system malfunction

• CMP sensor and projections of the camshaft sprocket malfunction

• Improper operation of variable valve timing control system

• Low engine compression

• PCV valve malfunction

• Clutch malfunction (MTX)

• ATX malfunction (ATX)

• Valve timing malfunction

• PCM 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. (See BEFORE SERVICE PRECAUTION [MZR 1.6].) (See AFTER SERVICE PRECAUTION [MZR 1.6].)

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.

STEP	INSPECTION	ACTION
1	Retrieve the PCM DTC using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) Is the DTC P2299:00 present?	Yes	Go to the applicable DTC inspection. (drive-by-wire control system operates with brake override system.) (See DTC P2299:00 [MZR 1.6].)
No	Go to the next step.
2	Inspect the following: • Air cleaner element • Electrical connections • Clutch malfunction (MTX) • Fuse malfunction • Fuel quality (such as proper octane, contamination, winter/summer blend) • Ignition wiring • No air leakage from the intake-air system • No restriction of the intake-air system • Smooth operation of throttle valve • Vacuum hose connection Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 2.
No	Go to the next step.
3	Connect the M-MDS to the DLC-2. If the engine stalls: • Perform the KOEO self test. (See KOEO/KOER SELF TEST [MZR 1.6].) If the engine does not stall: • Perform the KOEO or KOER self test. (See KOEO/KOER SELF TEST [MZR 1.6].) Are any continuous memory DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 1.6].)
No	Go to the next step.
4	Is the engine overheating?	Yes	Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”. (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 1.6].)
No	Go to the next step.
5	Access the following PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) • APP • MAF • RPM • TP1, TP2, TP REL • VPWR • VSS Monitor the each PID while driving the vehicle. Are all PIDs normal? (See PCM INSPECTION [MZR 1.6].)	Yes	Go to the next step.
No	APP: • Inspect if output signal from APP sensor changes smoothly. MAF: • Inspect for open circuit of the MAF sensor and related wiring harness intermittently. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 1.6].) RPM: • Inspect the CKP sensor and related harness for such as vibration, intermittent open/short circuit. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 1.6].) TP1, TP2, TP REL: • Inspect if output signal from the TP sensor changes smoothly. VPWR: • Inspect for open circuit intermittently. VSS: • Inspect the ABS or DSC system (MTX). Repair or replace the malfunctioning part according to the inspection results.
6	Visually inspect the CKP sensor and teeth of the crankshaft pulley. Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
No	Go to the next step.
7	Measure the gap between the CKP sensor and teeth of the crankshaft pulley. Is the gap within the specification? (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 1.6].)	Yes	Go to the next step.
No	Replace the crankshaft pulley. (See FRONT OIL SEAL REPLACEMENT [MZR 1.6].)
8	Inspect the spark plug conditions. (See SPARK PLUG INSPECTION [MZR 1.6].) Is the spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: • Inspect for fuel leakage from the fuel injector. Spark plug is grayish white: • Inspect for clogged the fuel injector. Repair or replace the malfunctioning part according to the inspection results.
No	Install the spark plugs on original cylinders. Go to the next step.
9	Perform the Drive-by-wire Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.6].) Does the throttle body operate properly?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the inspection results.
10	Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Repair or replace the malfunctioning part according to the inspection results.
No	Go to the next step.
11	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Perform the Active Command Modes Procedure and turn On the fuel pump using the FP PID. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) Is the fuel line pressure correct? (See FUEL LINE PRESSURE INSPECTION [MZR 1.6].)	Yes	Go to the next step.
No	Zero or low: • Inspect the fuel pump relay and the fuel pump unit related wiring harness. • If the wiring harness is normal: ― Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 1.6].) • If the wiring harness has a malfunction: ― Repair or replace the suspected wiring harness. High: • Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 1.6].)
12	Visually inspect for fuel leakage at the fuel injector O-ring and fuel line. Is the fuel line pressure held after the FP PID is turned Off? (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) (See FUEL LINE PRESSURE INSPECTION [MZR 1.6].)	Yes	Go to the next step.
No	Inspect the pressure regulator diaphragm condition. • If the condition is normal: ― Inspect the fuel injector. ― Repair or replace the malfunctioning part according to the inspection results. (See FUEL INJECTOR REMOVAL/INSTALLATION [MZR 1.6].) • If the condition is not normal: ― Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 1.6].)
13	Note • Following test is for engine stalling with the A/C on. If other symptom exists, go to the next step. Connect the pressure gauge to the A/C low and high pressure side lines. Turn the A/C on and measure low side and high side pressure. Are the pressure within the specifications? (See REFRIGERANT PRESSURE CHECK.)	Yes	Go to the next step.
No	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”. (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 1.6].) For other symptoms: • Inspect the following: ― Refrigerant charging amount ― Condenser fan operation • Repair or replace the malfunctioning part according to the inspection results.
14	Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 1.6].) Is there any malfunction?	Yes	Inspect for followings: • Exhaust gas leakage between exhaust manifold and A/F sensor. • Loose installation of A/F sensor. If there are no malfunctions detected: • Replace the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZR 1.6].) If there are malfunctions detected: • Repair or replace the malfunctioning part according to the inspection results. (See EXHAUST SYSTEM REMOVAL/INSTALLATION [MZR 1.6].)
No	Go to the next step.
15	Inspect the evaporative purge hose between the fuel tank and purge solenoid valve. Does the fuel flow into the evaporative purge hose?	Yes	Inspect the check valve (two-way). (See FUEL TANK INSPECTION [MZR 1.6].) Repair or replace the malfunctioning part according to the inspection results, if necessary.
No	Go to the next step.
16	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid valve side. Plug the opening end of the vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect the purge solenoid valve (stuck open mechanically). (See PURGE SOLENOID VALVE INSPECTION [MZR 1.6].) Inspect the EVAP control system. Repair or replace the malfunctioning part according to the inspection results, if necessary.
No	Go to the next step.
17	Visually inspect the CMP sensor and projections of the camshaft sprocket. Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, if necessary.
No	Go to the next step.
18	Perform the Variable Valve Timing Control System Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.6].) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
No	Go to the next step.
19	Inspect the engine compression. (See COMPRESSION INSPECTION [MZR 1.6].) Is there any malfunction?	Yes	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
No	Go to the next step.
20	Inspect the PCV valve operation. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 1.6].) Is there any malfunction?	Yes	Replace the PCV valve and the oil separator as a single unit. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 1.6].)
No	Inspect the following: • Check valve (two-way) • Clutch (MTX) • Engine mounts • Internal transaxle part (ATX) • Valve timing Repair or replace the malfunctioning part according to the inspection results.
21	Verify the test results. • If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 1.6].) • If malfunction remains, inspect related Service information perform repair or diagnosis. ― If vehicle repaired, troubleshooting completed. ― If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.6].)

STEP

INSPECTION

ACTION

Retrieve the PCM DTC using the M-MDS.

(See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].)

Is the DTC P2299:00 present?

Yes

Go to the applicable DTC inspection. (drive-by-wire control system operates with brake override system.)

(See DTC P2299:00 [MZR 1.6].)

Go to the next step.

Inspect the following:

• Air cleaner element

• Electrical connections

• Clutch malfunction (MTX)

• Fuse malfunction

• Fuel quality (such as proper octane, contamination, winter/summer blend)

• Ignition wiring

• No air leakage from the intake-air system

• No restriction of the intake-air system

• Smooth operation of throttle valve

• Vacuum hose connection

Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results.

Repeat Step 2.

Go to the next step.

Connect the M-MDS to the DLC-2.

If the engine stalls:

• Perform the KOEO self test.

(See KOEO/KOER SELF TEST [MZR 1.6].)

If the engine does not stall:

• Perform the KOEO or KOER self test.

(See KOEO/KOER SELF TEST [MZR 1.6].)

Are any continuous memory DTCs present?

Yes

Go to the appropriate DTC inspection.

(See DTC TABLE [MZR 1.6].)

Go to the next step.

Is the engine overheating?

Yes

Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.

(See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 1.6].)

Go to the next step.

Access the following PIDs using the M-MDS:

(See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].)

• APP

• MAF

• RPM

• TP1, TP2, TP REL

• VPWR

• VSS

Monitor the each PID while driving the vehicle.

Are all PIDs normal?

(See PCM INSPECTION [MZR 1.6].)

Yes

Go to the next step.

APP:

• Inspect if output signal from APP sensor changes smoothly.

MAF:

• Inspect for open circuit of the MAF sensor and related wiring harness intermittently.

(See MASS AIR FLOW (MAF) SENSOR INSPECTION [MZR 1.6].)

RPM:

• Inspect the CKP sensor and related harness for such as vibration, intermittent open/short circuit.

(See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 1.6].)

TP1, TP2, TP REL:

• Inspect if output signal from the TP sensor changes smoothly.

VPWR:

• Inspect for open circuit intermittently.

VSS:

• Inspect the ABS or DSC system (MTX).

Repair or replace the malfunctioning part according to the inspection results.

Visually inspect the CKP sensor and teeth of the crankshaft pulley.

Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results.

Go to the next step.

Measure the gap between the CKP sensor and teeth of the crankshaft pulley.

Is the gap within the specification?

(See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 1.6].)

Yes

Go to the next step.

Replace the crankshaft pulley.

(See FRONT OIL SEAL REPLACEMENT [MZR 1.6].)

Inspect the spark plug conditions.

(See SPARK PLUG INSPECTION [MZR 1.6].)

Is the spark plug wet, covered with carbon or grayish white?

Yes

Spark plug is wet or covered with carbon:

• Inspect for fuel leakage from the fuel injector.

Spark plug is grayish white:

• Inspect for clogged the fuel injector.

Repair or replace the malfunctioning part according to the inspection results.

Install the spark plugs on original cylinders.

Go to the next step.

Perform the Drive-by-wire Control System Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.6].)

Does the throttle body operate properly?

Yes

Go to the next step.

Repair or replace the malfunctioning part according to the inspection results.

Visually inspect the exhaust system part.

Is there any deformed exhaust system part?

Yes

Repair or replace the malfunctioning part according to the inspection results.

Go to the next step.

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

Perform the Active Command Modes Procedure and turn On the fuel pump using the FP PID.

(See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].)

Is the fuel line pressure correct?

(See FUEL LINE PRESSURE INSPECTION [MZR 1.6].)

Yes

Go to the next step.

Zero or low:

• Inspect the fuel pump relay and the fuel pump unit related wiring harness.

• If the wiring harness is normal:

― Replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 1.6].)

• If the wiring harness has a malfunction:

― Repair or replace the suspected wiring harness.

High:

• Replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 1.6].)

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

Is the fuel line pressure held after the FP PID is turned Off?

(See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].)

(See FUEL LINE PRESSURE INSPECTION [MZR 1.6].)

Yes

Go to the next step.

Inspect the pressure regulator diaphragm condition.

• If the condition is normal:

― Inspect the fuel injector.

― Repair or replace the malfunctioning part according to the inspection results.

(See FUEL INJECTOR REMOVAL/INSTALLATION [MZR 1.6].)

• If the condition is not normal:

― Replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 1.6].)

Note

• Following test is for engine stalling with the A/C on. If other symptom exists, go to the next step.

Connect the pressure gauge to the A/C low and high pressure side lines.

Turn the A/C on and measure low side and high side pressure.

Are the pressure within the specifications?

(See REFRIGERANT PRESSURE CHECK.)

Yes

Go to the next step.

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”.

(See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 1.6].)

For other symptoms:

• Inspect the following:

― Refrigerant charging amount

― Condenser fan operation

• Repair or replace the malfunctioning part according to the inspection results.

Inspect the A/F sensor.

(See AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 1.6].)

Is there any malfunction?

Yes

Inspect for followings:

• Exhaust gas leakage between exhaust manifold and A/F sensor.

• Loose installation of A/F sensor.

If there are no malfunctions detected:

• Replace the A/F sensor.

(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZR 1.6].)

If there are malfunctions detected:

• Repair or replace the malfunctioning part according to the inspection results.

(See EXHAUST SYSTEM REMOVAL/INSTALLATION [MZR 1.6].)

Go to the next step.

Inspect the evaporative purge hose between the fuel tank and purge solenoid valve.

Does the fuel flow into the evaporative purge hose?

Yes

Inspect the check valve (two-way).

(See FUEL TANK INSPECTION [MZR 1.6].)

Repair or replace the malfunctioning part according to the inspection results, if necessary.

Go to the next step.

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

Plug the opening end of the vacuum hose.

Drive the vehicle.

Does the engine condition improve?

Yes

Inspect the purge solenoid valve (stuck open mechanically).

(See PURGE SOLENOID VALVE INSPECTION [MZR 1.6].)

Inspect the EVAP control system.

Repair or replace the malfunctioning part according to the inspection results, if necessary.

Go to the next step.

Visually inspect the CMP sensor and projections of the camshaft sprocket.

Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results, if necessary.

Go to the next step.

Perform the Variable Valve Timing Control System Operation Inspection.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.6].)

Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results.

Go to the next step.

Inspect the engine compression.

(See COMPRESSION INSPECTION [MZR 1.6].)

Is there any malfunction?

Yes

Inspect for cause.

Repair or replace the malfunctioning part according to the inspection results.

Go to the next step.

Inspect the PCV valve operation.

(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 1.6].)

Is there any malfunction?

Yes

Replace the PCV valve and the oil separator as a single unit.

(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 1.6].)

Inspect the following:

• Check valve (two-way)

• Clutch (MTX)

• Engine mounts

• Internal transaxle part (ATX)

• Valve timing

Repair or replace the malfunctioning part according to the inspection results.

Verify the test results.

• If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 1.6].)

• If malfunction remains, inspect related Service information perform repair or diagnosis.

― If vehicle repaired, troubleshooting completed.

― If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.6].)