NO.27 SPARK PLUG CONDITION [13B-MSP]

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SPARK PLUG CONDITION
DESCRIPTION
Incorrect spark plug condition.
POSSIBLE CAUSE
Note
•  Inspecting the spark plugs condition can determine whether the problem is related to a specific spark plug or possibly all spark plugs.
Wet/carbon stuck on specific plug:
•  Spark—Weak, not visible
•  Air/fuel mixture—Excessive fuel injection volume
•  Compression—No compression, low compression
•  Faulty spark plug
Grayish white with specific plug:
•  Air/fuel mixture—Insufficient fuel injection volume
•  Faulty spark plug
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 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 REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.
Caution
•  Disconnecting/connecting quick release connector without cleaning it may possibly cause damage to fuel pipe and quick release connector. Always clean 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
Remove all the spark plugs.
Inspect the spark plug condition.
Is the spark plug condition normal?
Yes
Troubleshooting completed.
No
Specific plug is wet or covered with carbon:
Go to the next step.
Specific plug looks grayish white:
Go to Step 13.
All plugs are wet or covered with carbon:
Go to Step 15.
All plugs look grayish white:
Go to Step 27.
2
Is the spark plug wet/covered with carbon by engine oil?
Yes
Working up and down inspect all the areas related to the oil.
No
Go to the next step.
3
Inspect the spark plug for the following:
•  Cracked insulator
•  Heat range
•  Air gap
•  Worn electrode
Is the spark plug normal?
Yes
Go to the next step.
No
Replace the spark plug.
4
Inspect the engine compression.
(See COMPRESSION INSPECTION [13B-MSP].)
Is it normal?
Yes
Go to Step 10.
No
Go to the next step.
5
Perform the Metering Oil Pump Control Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [13B-MSP].)
Does the metering oil pump control operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
After that overhaul or replace the engine.
6
Check the engine oil condition.
Is engine oil low viscosity and/or is there a gasoline odor?
Yes
Replace the engine oil.
After that overhaul or replace the engine.
No
Go to the next step.
7
Inspect the oil pressure.
(See OIL PRESSURE INSPECTION [13B-MSP].)
Is the oil pressure within the specification?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
After that overhaul or replace the engine.
8
Turn the ignition switch off.
Disconnect the fuel line quick release connector and install fuel gauge to fuel line.
Start the engine and run it at idle.
Measure the fuel line pressure at idle.
Is the fuel line pressure correct at idle?
(See FUEL LINE PRESSURE INSPECTION [13B-MSP].)
Yes
Go to the next step.
No
Replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
After that overhaul or the replace engine.
9
Check the oil pipe between the metering oil pump and the metering oil nozzle.
Is there any air and/or clogging in the oil pipe?
Yes
Inspect and repair for leakage and/or clogging in the oil passage at the engine.
After that overhaul or replace the engine.
No
Overhaul or replace the engine.
10
Install all the spark plugs.
Perform the spark test at the suspected faulty rotor.
Is a strong blue spark visible?
(Compare with normal rotor.)
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts.
11
Perform the fuel pump control system inspection.
Does the fuel pump control system operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to inspection results.
12
Inspect the fuel line pressure.
(See FUEL LINE PRESSURE INSPECTION [13B-MSP].)
Is the fuel line pressure correct?
Yes
Inspect the fuel injector for the following:
(See FUEL INJECTOR INSPECTION [13B-MSP].)
•  Open or short in injector
•  Leakage
•  Injection volume
No
Zero or low:
Inspect the fuel pump relay and the fuel pump circuit.
Inspect for clogged fuel line.
If normal, replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
High:
Replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
13
Inspect the spark plug for the following.
•  Heat range
•  Air gap
Is the spark plug normal?
Yes
Go to the next step.
No
Replace the spark plug.
14
Perform the fuel injector operation inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [13B-MSP].)
Does the fuel injector operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts, according to the fuel injector operation inspection results.
15
Is the air cleaner element free of restrictions?
Yes
Go to the next step.
No
Replace the air cleaner element.
16
Perform the spark test.
Is a strong blue spark visible at each spark plug?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts.
17
Perform the fuel pump control system inspection.
Does the fuel pump control system operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
18
Inspect the fuel line pressure.
(See FUEL LINE PRESSURE INSPECTION [13B-MSP].)
Is the fuel line pressure correct?
Yes
Go to the next step.
No
Zero or low:
Inspect the fuel pump relay and the fuel pump circuit.
Inspect for clogged fuel line.
If normal, replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
High:
Replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
19
Inspect the following PIDs:
•  ECT
•  O2S11 (When the engine can be started.)
•  O2S12 (When the engine can be started.)
•  MAF
(See PCM INSPECTION [13B-MSP].)
Are the PIDs normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts.
20
Perform the purge control inspection.
(When engine can be started)
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [13B-MSP].)
Is the purge control correct?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts.
21
Inspect the engine compression.
(See COMPRESSION INSPECTION [13B-MSP].)
Is it normal?
Yes
Go to Step 27.
No
Go to the next step.
22
Perform the metering oil pump control inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [13B-MSP].)
Does the metering oil pump control operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
After that overhaul or replace the engine.
23
Check the engine oil condition.
Is the engine oil low viscosity and/or is there a gasoline odor?
Yes
Replace the engine oil.
After that overhaul or replace the engine.
No
Go to the next step.
24
Inspect the oil pressure.
(See OIL PRESSURE INSPECTION [13B-MSP].)
Is the oil pressure within the specification?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
After that overhaul or replace the engine.
25
Turn the ignition switch off.
Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line.
Start engine and run it at idle.
Measure the fuel line pressure at idle.
Is the fuel line pressure correct at idle?
(See FUEL LINE PRESSURE INSPECTION [13B-MSP].)
Yes
Go to the next step.
No
Replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
After that overhaul or replace the engine.
26
Check the oil pipe between the metering oil pump and the metering oil nozzle.
Is there any air and/or clogging in the oil pipe?
Yes
Inspect and repair for leakage and/or clogging in the oil passage at the engine.
After that overhaul or replace the engine.
No
Overhaul or replace the engine.
27
When the engine cannot be started, inspect the intake-air system for air leakage.
When the engine can be started, perform the intake manifold vacuum inspection.
Is air sucked in from the intake-air system?
Yes
Repair or replace the malfunctioning part.
No
Go to the next step.
28
Perform the fuel pump control system inspection.
Does the fuel pump control system operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
29
Inspect the fuel line pressure.
(See FUEL LINE PRESSURE INSPECTION [13B-MSP].)
Is the fuel line pressure correct?
Yes
Inspect the following PIDs:
•  ECT
•  O2S11
•  O2S12
•  MAF
(See PCM INSPECTION [13B-MSP].)
Inspect the PCM GND condition.
No
Zero or low:
Inspect the fuel pump relay and the fuel pump circuit.
Inspect for clogged fuel line.
If normal, replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
High:
Replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [13B-MSP].)
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•  Verify test results.
―  If normal, return to the diagnostic index to service any additional symptoms.
―  If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis.