NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [MZR 1.6]

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4

HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
DESCRIPTION
•  The starter cranks the engine at normal speed but the engine requires excessive cranking time before starting.
―  The battery is in normal condition.
POSSIBLE CAUSE
•  Air cleaner restriction
•  Cracks on intake-air system parts
•  Loose bands on intake-air system
•  Poor fuel quality
•  Vacuum leakage
•  Air leakage from intake-air system
•  Engine overheating
•  Ignition coil and related wiring harness malfunction
•  Spark plug malfunction
•  CKP sensor and teeth of the crankshaft pulley malfunction
•  Improper operation of drive-by-wire control system
•  Inadequate fuel pressure
•  Pressure regulator malfunction
•  Purge solenoid valve malfunction (stuck open)
•  MAF sensor malfunction
―  MAF sensor contamination
―  Incorrect MAF sensor ground voltage
•  Restriction in exhaust system
•  Starting system malfunction
•  PCV valve malfunction
•  Improper air/fuel mixture ratio control
•  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 REPAIR PROCEDURE" 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.

Diagnostic Procedure

STEP

INSPECTION

ACTION
1
Inspect the following:
•  Air cleaner restriction
•  Cracks on intake-air system parts
•  Loose bands on intake-air system
•  Proper fuel quality (such as proper octane, contamination, winter/summer blend)
•  Vacuum leakage
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 1.
No
Go to the next step.
2
Connect the M-MDS to the DLC-2.
Perform the KOEO or KOER self test.
(See KOEO/KOER SELF TEST [MZR 1.6].)
Are any DTCs present?
Yes
Go to the appropriate DTC inspection.
(See DTC TABLE [MZR 1.6].)
No
Go to the next step.
3
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.
4
Inspect the ignition coil and related wiring harnesses condition (intermittent open or short circuit) for all cylinders.
(See IGNITION COIL 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.
5
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.
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 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
Attempt to start the engine at part throttle.
Does the engine run smoothly at part throttle?
Yes
Perform the Drive-by-wire Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.6].)
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
9
Install the fuel pressure gauge between the fuel pipe and the fuel distributor.
Perform the Active Command Modes Procedure.
Turn On fuel pump using FP PID in output state control of data logger function.
(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 there is no malfunction:
•  Replace the fuel pump unit.
―  If there is a malfunction:
•  Repair or replace the suspected wiring harness.
High:
•  Replace the fuel pump unit.
10
Is the fuel line pressure held after the FP PID is turned Off?
(See FUEL LINE PRESSURE INSPECTION [MZR 1.6].)
Yes
Go to the next step.
No
Inspect the pressure regulator diaphragm condition.
•  If condition is normal:
―  Inspect the fuel injector.
―  Repair or replace the malfunctioning part according to the inspection results.
•  If condition is not normal:
―  Replace the pressure regulator.
11
Disconnect the vacuum hose from the purge solenoid valve and plug opening end of the vacuum hose.
Start the engine.
Is the starting condition improved?
Yes
Inspect the purge solenoid valve (stuck open).
(See PURGE SOLENOID VALVE INSPECTION [MZR 1.6].)
Replace the purge solenoid valve, if necessary.
(See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [MZR 1.6].)
No
Go to the next step.
12
Inspect the MAF sensor for the following:
•  Contamination
•  MAF sensor terminal B voltage (ground circuit)
Is there any contamination?
Yes
Replace the MAF/IAT sensor.
(See MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZR 1.6].)
No
Go to the next step.
13
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.
14
Inspect the starting system.
(See STARTER 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.
15
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 for loose connectors or poor terminal contact.
•  If there is any malfunction:
―  Repair or replace the malfunctioning part according to the inspection results.
•  If there is no malfunction:
―  Inspect the valve timing.
•  Repair or replace the malfunctioning part according to the inspection results if necessary.
16
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].)