NO.27 SPARK PLUG CONDITION [MZR 1.5, MZR 1.6]

id0103e0804400

27

SPARK PLUG CONDITION
DESCRIPTION
•  Incorrect spark plug condition.
POSSIBLE CAUSE
Note
•  Inspecting the spark plug condition can determine whether problem is related to a specific cylinder possibly all cylinders.
Wet/carbon stuck on specific plug:
•  Spark—Weak, not visible
•  Air/fuel mixture—Excessive fuel injection volume
•  Compression—No compression, low compression
•  Spark plug malfunction
Grayish white with specific plug:
•  Air/fuel mixture—Insufficient fuel injection volume
•  Spark plug malfunction
Wet/carbon is stuck on all plugs:
•  Spark—Spark weak
•  Air/fuel mixture—Too rich
•  Compression—Low compression
•  Clogging in intake/exhaust system
Grayish white with all plugs:
•  Air/fuel mixture—Too lean
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 1.5, MZR 1.6].) (See AFTER SERVICE PRECAUTION [MZR 1.5, 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
Remove the all spark plugs.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)
Inspect the spark plug condition.
(See SPARK PLUG INSPECTION [MZR 1.5, MZR 1.6].)
Is there any malfunction?
Yes
Specific plug is wet or covered with carbon:
•  Go to the next step.
Specific plug looks grayish white:
•  Go to Step 7.
All plugs are wet or covered with carbon:
•  Go to Step 10.
All plugs look grayish white:
•  Go to Step 16.
No
DTC troubleshooting completed.
2
Are the spark plugs wet/covered with carbon by engine oil?
Yes
Inspect the all areas related to oil working up and down.
Repair or replace the malfunctioning part according to the inspection results, if necessary.
No
Go to the next step.
3
Inspect the spark plug for the following:
•  Air gap
•  Cracked insulator
•  Heat range
•  Worn electrode
Is there any malfunction?
Yes
Replace the spark plug.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)
No
Go to the next step.
4
Inspect the compression pressure at suspected malfunctioning cylinder.
(See COMPRESSION INSPECTION [MZR 1.5, MZR 1.6].)
Is the compression pressure correct?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
5
Install the all spark plugs.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)
Perform the Spark Test at the suspected malfunctioning cylinder.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.5, MZR 1.6].)
Is the strong blue spark visible (compare with normal cylinder)?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
6
Perform the “FUEL LINE PRESSURE INSPECTION”.
(See FUEL LINE PRESSURE INSPECTION [MZR 1.5, MZR 1.6].)
Is the fuel line pressure correct?
Yes
Inspect the fuel injector.
(See FUEL INJECTOR INSPECTION [MZR 1.5, MZR 1.6].)
Replace the fuel injector, if necessary.
(See FUEL INJECTOR REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)
No
Zero or low:
•  Inspect the fuel pump and the fuel pump relay related circuit.
―  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.
7
Inspect the spark plug for the following:
•  Air gap
•  Heat range
Is there any malfunction?
Yes
Replace the spark plug.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)
No
Go to the next step.
8
Switch the ignition to off.
Disconnect the suspected fuel injector connector.
Switch the ignition to ON (engine off).
Measure the voltage at fuel injector terminal A (wiring harness-side).
Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open or short circuit.
9
Perform the Fuel Injector Operation Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.5, 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.
10
Inspect the air cleaner element.
(See AIR CLEANER ELEMENT INSPECTION [MZR 1.5, MZR 1.6].)
Is the air cleaner element free of restrictions?
Yes
Go to the next step.
No
Replace the air cleaner element.
11
Perform the Spark Test.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.5, MZR 1.6].)
Is the 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.
12
Perform the “FUEL LINE PRESSURE INSPECTION”.
(See FUEL LINE PRESSURE INSPECTION [MZR 1.5, MZR 1.6].)
Is the fuel line pressure correct?
Yes
Go to the next step.
No
Zero or low:
•  Inspect the fuel pump, fuel pump relay related circuit and main 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.
13
Access the following PIDs using the M-MDS:
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.5, MZR 1.6].)
•  ECT
•  MAF
•  O2S11 (when engine can be started)
•  O2S12 (when engine can be started)
Are all PIDs normal?
(See PCM INSPECTION [MZR 1.5, MZR 1.6].)
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
14
Perform the Purge Control System Inspection when the engine can be started.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.5, 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 engine compression.
(See COMPRESSION INSPECTION [MZR 1.5, MZR 1.6].)
Is there any malfunction?
Yes
Inspect for cause.
Repair or replace the malfunctioning part according to the inspection results.
No
Inspect the deformed exhaust system part.
Repair or replace the malfunctioning part according to the inspection results.
16
Inspect the intake-air system for air leakage and perform the Intake Manifold Vacuum Inspection when the engine cannot be started.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.5, MZR 1.6].)
Is the air sucked in from intake-air system?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
17
Perform the “FUEL LINE PRESSURE INSPECTION”.
(See FUEL LINE PRESSURE INSPECTION [MZR 1.5, MZR 1.6].)
Is the fuel line pressure correct?
Yes
Access the following PIDs using the M-MDS:
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.5, MZR 1.6].)
•  ECT
•  MAF
•  O2S11
•  O2S12
―  If the PIDs are not normal:
•  Repair or replace the malfunctioning part according to the inspection results.
―  If the PIDs are normal:
•  Inspect the PCM ground condition.
•  Repair or replace the malfunctioning part according to the inspection results, if necessary.
No
Zero or low:
•  Inspect the 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.
18
Verify the test results.
•  If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 1.5, 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 PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)