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Home >> Mazda >> 2011 >> RX-8 R3, 1.3 4 >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting [Engine Mechanical] >> No. 29 Spark Plug Condition

No. 29 Spark Plug Condition

29 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 SERVICE PRECAUTION and AFTER SERVICE PRECAUTION .
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 spark plugs.
(See SPARK PLUG REMOVAL/INSTALLATION ).
Inspect the spark plug condition.
(See SPARK PLUG INSPECTION ).
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 26.
2 Is the spark plug wet/covered with carbon by the engine oil? Yes Working up and down inspect all 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.
(See SPARK PLUG REMOVAL/INSTALLATION ).
4 Inspect the engine compression.
(See COMPRESSION INSPECTION ).
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 ).
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 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.
7 Inspect the oil pressure.
(See OIL PRESSURE INSPECTION ).
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 ).		 Yes Go to the next step.
No Replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION ).
After that overhaul or replace the engine.
9 Check the oil pipe between metering oil pump and 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 spark plugs.
(See SPARK PLUG REMOVAL/INSTALLATION ).
Perform the Spark Test at the suspected faulty rotor.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION ).
Is a strong blue spark visible? (compare with normal rotor).		 Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
11 Perform the Fuel Pump Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION 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.
12 Inspect the fuel line pressure.
(See FUEL LINE PRESSURE INSPECTION ).
Is the fuel line pressure correct?		 Yes Inspect the fuel injector for the following:
(See FUEL INJECTOR INSPECTION ).
  • Open or short in injector
  • Leakage
No Zero or low: 
High: 
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.
(See SPARK PLUG REMOVAL/INSTALLATION ).
14 Perform the Fuel Injector Operation Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION ).
Does the fuel injector operate properly?		 Yes Inspect for restrict suspect rotor side fuel injectors.
Service if necessary.
No Repair or replace the malfunctioning part according to the 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.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION ).
Is a strong blue spark visible at each spark plug?		 Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
17 Perform the Fuel Pump Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION 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 ).
Is the fuel line pressure correct?		 Yes Go to the next step.
No Zero or low: 
High: 
19 Perform the Purge Control System Inspection when the engine can be started.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION ).
Is the purge control correct?		 Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
20 Inspect the engine compression.
(See COMPRESSION INSPECTION ).
Is it normal?		 Yes Inspect the following PIDs:
(See ON-BOARD DIAGNOSTIC TEST ).
  • ECT
  • O2S11 (When the engine can be started).
  • O2S12 (When the engine can be started).
  • MAF

Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
21 Perform the Metering Oil Pump Control Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION ).
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.
22 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.
23 Inspect the oil pressure.
(See OIL PRESSURE INSPECTION ).
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.
24 Turn the ignition switch off.
Disconnect the fuel line quick release connector and install the fuel gauge to the 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 ).		 Yes Go to the next step.
No Replace the fuel pump unit.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION ).
After that overhaul or replace the engine.
25 Check the oil pipe between metering oil pump and 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.
26 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.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION ).
Is air sucked in from the intake-air system?		 Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
27 Perform the Fuel Pump Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION 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.
28 Inspect the fuel line pressure.
(See FUEL LINE PRESSURE INSPECTION ).
Is the fuel line pressure correct?		 Yes Inspect the following PIDs:
(See ON-BOARD DIAGNOSTIC TEST ).
  • ECT
  • O2S11
  • O2S12
  • MAF

Inspect the PCM GND condition.
No Zero or low: 
High: 
29 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 On-line Repair Information and perform 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.
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