NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [MZR 1.8, MZR 2.0, MZR 2.5]

id0103d4801000

4

HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
DESCRIPTION
•  Starter cranks engine at normal speed but engine requires excessive cranking time before starting.
POSSIBLE CAUSE
•  Vacuum leakage
•  Poor fuel quality
•  Air leakage from intake-air system
•  Intake-air system restriction
•  PCM DTC is stored
•  Cooling system malfunction
•  Ignition coil related wiring harness malfunction
•  Ignition system malfunction
•  Spark plug malfunction
•  CKP sensor and teeth of crankshaft pulley malfunction
•  Improper operation of electronic throttle control system
•  Excessive or insufficient fuel pressure
―  Fuel pump relay or fuel pump circuit malfunction
―  Clogging fuel line
―  Pressure regulator malfunction (built-in fuel pump unit)
―  Fuel pump unit malfunction
•  Fuel leakage from fuel system
•  Purge solenoid valve malfunction
•  MAF sensor malfunction
•  Restriction in exhaust system
•  EGR valve malfunction
•  Starting system 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 1.8, MZR 2.0, MZR 2.5].) (See AFTER SERVICE PRECAUTION [MZR 1.8, 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
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
Perform the PCM DTC inspection using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)
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 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
4
Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders.
Is there any malfunction?
Yes
Repair or replace the suspected wiring harness.
No
Go to the next step.
5
Perform the Spark Test.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
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 spark test result.
6
Verify the spark plug conditions when the spark plug removed in Step 5.
(See SPARK PLUG INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
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 clogging.
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.
7
Visually inspect the CKP sensor and teeth of crankshaft pulley.
(See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
8
Attempt to start the engine at part throttle.
Does the engine run smoothly at part throttle?
Yes
Inspect the electronic throttle control system operation.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
9
Inspect the fuel line pressure.
(See FUEL LINE PRESSURE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Zero or low:
•  Inspect the fuel pump relay and the fuel pump circuit.
•  Inspect the fuel line for clogging.
―  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.
10
Is the fuel line pressure held after ignition is off?
(See FUEL LINE PRESSURE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Yes
Go to the next step.
No
Inspect the fuel injector.
(See FUEL INJECTOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  If the fuel injector has malfunction:
―  Replace the fuel injector.
•  If the fuel injector is normal:
―  Replace the fuel pump unit.
11
Disconnect the vacuum hose from purge solenoid valve and plug opening end of vacuum hose.
Switch the ignition to ON (engine off).
Is the starting condition improved?
Yes
Inspect if the purge solenoid valve is stuck open.
(See PURGE SOLENOID VALVE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Repair or replace the malfunctioning part according to the inspection results.
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 malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
13
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.
14
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 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
15
Inspect the starting system.
(See STARTER INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Repair or replace components as required.
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:
―  Remove the EGR valve and visually inspect for a mechanically stuck EGR valve.
―  Repair or replace the malfunctioning part according to the inspection results.
16
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, reprogram the PCM if a later calibration is available. Retest.