NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [MZR 2.0, MZR 2.5]


id0103e1801700

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 the 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
•  Improper operation of A/C system
•  Erratic signal or no signal from CMP sensor
•  Air leakage from intake air system parts
•  Purge solenoid valve malfunction
•  Improper operation of electronic throttle control system
•  EGR valve malfunction
•  Erratic signal from CKP sensor
•  Low engine compression
•  Vacuum leakage
•  Poor fuel quality
•  Main relay intermittent malfunction
•  Throttle body malfunction
•  Engine overheating
•  Spark plug malfunction
•  Improper operation of air/fuel mixture ratio control
•  Improper operation of variable tumble control
•  Erratic signal to ignition coil
•  Air cleaner restriction
•  Fuel flow into evaporative purge hose
•  Improper valve timing due to jumping out timing chain
•  Restriction in exhaust system
•  Intermittent open or short circuit in fuel pump circuit
•  Inadequate fuel pressure
•  Fuel pump mechanical malfunction
•  Check valve (two-way) malfunction integrated with fuel tank
•  Fuel leakage from fuel injector
•  Fuel injector clogging
•  Fuel line restriction or clogging
•  Pressure regulator malfunction (built-in fuel pump unit)
•  Erratic signal form APP sensor
•  Erratic signal form TP sensor
•  Intermittent open or short circuit of MAF sensor, TP sensor, APP sensor and VSS
•  ATX malfunction (ATX)
•  Clutch slippage (MTX)
•  Improper operation of variable intake air control
•  Loose attaching bolts or worn engine mounts
•  PCV valve malfunction
•  PCM malfunction
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 [MZR 2.0, MZR 2.5].) (See AFTER SERVICE PRECAUTION [MZR 2.0, MZR 2.5].)
Caution
•  Disconnecting/connecting the quick release connector without cleaning it may cause damage to the fuel pipe and the quick release connector. Always clean the 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
Retrieve the PCM DTC using the M-MDS.
Is the DTC P2299:00 present?
Yes
Go to the applicable DTC inspection. (Electronic throttle control system operates with brake override system.)
No
Go to the next step.
2
Inspect the following:
•  Vacuum connection
•  Air cleaner element
•  No air leakage from intake air system
•  No restriction of the intake air system
•  Proper sealing of intake manifold and components attached to intake manifold: such as EGR valve
•  Ignition wiring
•  Fuel quality (such as proper octane, contamination, winter/summer blend)
•  Electrical connections
•  Smooth operation of the throttle valve
Are all items normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 2.
3
Connect the M-MDS to the DLC-2.
Switch the ignition to ON (engine off).
Retrieve any DTCs.
Are any DTCs present?
Yes
Go to the appropriate DTC inspection.
No
Go to the next step.
4
Is the engine overheating?
Yes
Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.
No
Go to the next step.
5
Connect the M-MDS to the DLC-2.
Access the APP1, APP2, RPM, VPWR, MAF, TP REL and VSS PIDs using the M-MDS while driving the vehicle.
Are the PIDs within specification?
Yes
Go to the next step.
No
APP1, APP2 PIDs:
•  Inspect if the output signal from the APP sensor changes smoothly.
RPM PID:
•  Inspect the CKP sensor and related wiring harness for vibration or an intermittent open/short circuit.
VPWR PID:
•  Inspect for an intermittent open circuit.
MAF PID:
•  Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness.
TP REL PID:
•  Inspect if the output signal from the TP sensor changes smoothly.
VSS PID:
•  Inspect for an intermittent open circuit in the VSS and related wiring harness.
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
Repair or replace the malfunctioning part according to the inspection results.
7
Inspect the spark plug conditions.
Are 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 injector.
Spark plug is grayish white:
•  Inspect for a clogged fuel injector.
Repair or replace the malfunctioning part according to the inspection results.
No
Install the spark plugs on original cylinders, then go to the next step.
8
Perform the Electronic Throttle Control System Inspection.
Does the electronic throttle control system function properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
9
Visually inspect for deformed exhaust system parts.
Are there any deformed exhaust system parts?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
10
Inspect the fuel line pressure.
Is the fuel line pressure correct?
Yes
Go to the next step.
No
Zero or low:
•  Inspect the following:
―  Fuel pump relay and the fuel pump circuit
―  Fuel line for clogging
•  If there is a malfunction, repair or replace the malfunctioning part according to the inspection results.
•  If there is no malfunction, replace the fuel pump unit.
High:
•  Replace the fuel pump unit.
11
Visually inspect for fuel leakage at the fuel injector O-ring and fuel line.
Repair or replace the malfunctioning part according to the inspection results.
Is the fuel line pressure held after the ignition is off?
Yes
Go to the next step.
No
Inspect the fuel injector.
•  If the fuel injector has a malfunction:
―  Replace the fuel injector.
•  If the fuel injector is normal:
―  Replace the fuel pump unit.
12
Note
•  The following test is for an engine stall with the A/C on. If other symptoms exist, go to the next step.
Connect a pressure gauge to the A/C low and high pressure side lines.
Turn the A/C on and measure the low side and high side pressure.
Are the pressures within the specifications?
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”.
For other symptoms:
•  Inspect the following:
―  Refrigerant charging amount
―  Condenser fan operation
•  Repair or replace the malfunctioning part according to the inspection results.
13
Note
•  The following test should be performed for symptoms with the cruise control on. If other symptoms exist, go to the next step.
Inspect the cruise control system.
Is the cruise control system normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
14
Inspect the A/F sensor.
Is there any malfunction?
Yes
Inspect for following:
•  Exhaust gas leakage between exhaust manifold and A/F sensor
•  Loose installation of A/F sensor
―  If there are no malfunctions:
―  If there is a malfunction:
•  Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
15
Inspect the evaporative purge hose between the fuel tank and the purge solenoid valve.
Does the fuel flow into the evaporative purge hose?
Yes
Inspect the check valve.
Repair or replace the malfunctioning part according to the inspection results.
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 open end of the vacuum hose.
Drive the vehicle.
Does the engine condition improve?
Yes
Inspect the following:
•  Purge solenoid valve
•  Evaporative emission control system
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
17
Visually inspect the CMP sensor and teeth of the camshaft.
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
18
Perform the Variable Tumble Control Operation Inspection.
Is the variable tumble control normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
19
Inspect the EGR system.
Is the EGR system normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
20
Is the engine compression correct?
Yes
Go to the next step.
No
Inspect for cause.
21
Inspect the PCV valve.
Is there any malfunction?
Yes
Replace the PCV valve and oil separator as a single unit.
No
Inspect the following:
•  Check valve (two-way)
•  Internal transaxle part (ATX)
•  Clutch (MTX)
•  EGR valve (mechanical stuck)
•  Engine mounts
•  Valve timing
Repair or replace the malfunctioning part according to the inspection results.
22
•  Verify the test results.
―  If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0, MZR 2.5].)
―  If a malfunction remains, inspect the related Service Information perform repair or diagnosis.
•  If the vehicle repaired, troubleshooting is completed.
•  If the vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)