NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [MZR 1.3, MZR 1.5]

id0103d7801000

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
Note
•  If the ignition is not switched off (to LOCK or ACC) after the engine stalls, and then an engine restart is attempted, the PCM corrects the difference between CKP sensor and CMP sensor signals caused by engine stalling, which may result in more time needed to restart the engine.
•  Air cleaner restriction
•  Cracks on intake-air system parts
•  Loose bands on intake-air system
•  Poor fuel quality
•  Vacuum leakage
•  PCM DTC is stored
•  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
―  Fuel pump mechanical malfunction
―  Pressure regulator malfunction (built-into fuel pump unit)
―  Check valve malfunction (built-into fuel pump unit)
―  Restriction in fuel line
―  Fuel pump relay or fuel pump circuit 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
•  EGR valve malfunction
•  Improper valve timing
•  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 “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual. (See BEFORE SERVICE PRECAUTION [MZR 1.3, MZR 1.5].) (See AFTER SERVICE PRECAUTION [MZR 1.3, MZR 1.5].)
Caution
•  Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to fuel pipe and 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
INSPECT RELATED PART CONDITION
•  Inspect the following:
―  Vacuum leakage
―  Proper fuel quality (such as proper octane, contamination, winter/summer blend)
―  Loose bands on intake-air system
―  Cracks on intake-air system parts
―  Intake-air system restriction (such as air cleaner element, fresh air duct)
•  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
VERIFY PCM DTC
•  Perform the PCM DTC inspection using the M-MDS.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.3, MZR 1.5].)
No
Go to the next step.
3
VERIFY IF MALFUNCTION CAUSE IS OVERHEATING
•  Is the engine overheating?
Yes
Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.
(See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 1.3, MZR 1.5].)
No
Go to the next step.
4
DETERMINE IF MALFUNCTION CAUSE IS EVAPORATIVE EMISSION CONTROL SYSTEM OR OTHER
•  Disconnect the vacuum hose from purge solenoid valve and plug opening end of vacuum hose.
•  Start the engine.
•  Is the starting condition improved?
Yes
Inspect if the purge solenoid valve is stuck open.
(See PURGE SOLENOID VALVE INSPECTION [MZR 1.3, MZR 1.5].)
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
5
INSPECT MAF SENSOR
•  Inspect the MAF sensor for the following:
―  Contamination
―  MAF sensor terminal B voltage (ground circuit)
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
6
INSPECT PCM FOR POOR GROUND
•  Verify the PCM ground point condition.
•  Is there any ground point loose or lifting in the PCM?
Yes
Repair the ground point.
No
Go to the next step.
7
INSPECT IGNITION SYSTEM RELATED WIRING HARNESS
•  Inspect the ignition coil and related wiring harness condition (intermittent open or short circuit) for all cylinders.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
8
INSPECT IGNITION SYSTEM OPERATION
•  Perform the Spark Test.
•  Is a strong blue spark visible at each cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
9
VERIFY SPARK PLUG CONDITION
•  Verify the spark plug conditions when the spark plug removed in Step 8.
•  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 fuel injector.
Spark plug is grayish white:
•  Inspect the fuel injector for restriction.
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.
10
INSPECT CKP SENSOR AND PULSE WHEEL
•  Visually inspect the CKP sensor and teeth of crankshaft pulley.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
11
INSPECT CKP SENSOR AIR GAP
•  Measure the gap between CKP sensor and teeth of the crankshaft pulley.
•  Is the gap within the specification?
Yes
Go to the next step.
No
Replace the crankshaft pulley.
12
DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER
•  Attempt to start the engine at part throttle.
•  Does the engine run smoothly at part throttle?
Yes
Inspect the drive-by-wire control system operation.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.3, MZR 1.5].)
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
13
INSPECT FUEL LINE PRESSURE
•  Install the fuel pressure gauge between the fuel pipe and the fuel distributor.
•  Inspect the fuel line pressure.
•  Is there any malfunction?
Yes
Zero or low:
•  Inspect the fuel pump relay and fuel pump circuit.
•  Inspect the fuel line for restriction.
―  If there is any 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.
No
Go to the next step.
14
INSPECT FUEL LINE HOLD PRESSURE FOR FUEL LEAKAGE
•  Is the fuel line pressure held after the FP PID is turned Off?
Yes
Go to the next step.
No
Inspect the fuel line for leakage.
•  If there is any malfunction:
―  Repair or replace the malfunctioning part according to the inspection results.
•  If there is no malfunction:
―  Replace the fuel pump unit. (check valve malfunction)
15
INSPECT EXHAUST SYSTEM
•  Visually inspect the exhaust system part.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
16
INSPECT EGR VALVE FOR STUCK
•  Inspect the engine condition while tapping the EGR valve housing.
•  Does the engine condition improve?
Yes
Replace the EGR valve.
(See EGR VALVE REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
No
Go to the next step.
17
INSPECT STARTING SYSTEM
•  Inspect the starting system.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
18
INSPECT PCV VALVE
•  Inspect the PCV valve operation.
•  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 1.3, MZR 1.5].)
No
Go to the next step.
19
INSPECT IF MALFUNCTION CAUSE IS EGR VALVE MECHANICAL STUCK OR VALVE TIMING
•  Remove the EGR valve and visually inspect the EGR valve (mechanically stuck).
•  Is there any malfunction?
Yes
Replace the EGR valve.
(See EGR VALVE REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
No
Inspect the valve timing.
Repair or replace the malfunctioning part according to the inspection results.
20
Verify test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.