Diagnostic procedure
WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.
NO.29 SPARK PLUG CONDITION 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. |
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| 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:
Is the spark plug normal? |
Yes | Go to the next step. | ||
| No | Replace the spark plug. | ||||
| 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 METERING OIL PUMP CONTROL 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. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 6 | Check the engine oil condition. Is engine oil low viscosity and/or is there a gasoline odor? |
Yes | Replace the engine oil. Inspect the ECT sensor and the related wiring harnesses. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .) After that overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 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. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 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 the replace engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 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. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| No | Overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 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 | Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line. Short the check connector terminal F/P to the body GND using a jumper wire. Turn the ignition switch to the ON position (Engine off). Is the fuel line pressure correct with the ignition switch at ON? Fuel line pressure
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Yes | Inspect the fuel injector for the following: (See FUEL INJECTOR INSPECTION .)
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| 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 .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .) |
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| 13 | Inspect the spark plug for the following.
Is the spark plug normal? |
Yes | Go to the next step. | ||
| No | Replace the spark plug. | ||||
| 14 | Remove the suspected fuel injector. Inspect the following: (See FUEL INJECTOR INSPECTION .)
Are all the above items normal? |
Yes | Inspect for an open circuit between the suspected fuel injector connector terminal and the PCM connector at the following terminals: Front rotor:
Rear rotor:
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| No | Replace the fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION .) |
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| 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 | Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line. Short the check connector terminal F/P to the body GND using a jumper wire. Turn the ignition switch to the ON position (Engine off) Is the fuel line pressure correct with the ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION .) Fuel line pressure
|
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 .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .) |
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| 19 | Inspect the following PIDs:
(See PCM INSPECTION .) 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 PURGE CONTROL SYSTEM INSPECTION .) 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 .) Is it normal? |
Yes | Go to Step 27. | ||
| No | Go to the next step. | ||||
| 22 | Perform the metering oil pump control inspection. (See METERING OIL PUMP CONTROL 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. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 23 | Check the engine oil condition. Is the engine oil low viscosity and/or is there a gasoline odor? |
Yes | Replace the engine oil. Inspect the ECT sensor and the related wiring harnesses. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .) After that overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| No | Go to the next step. | ||||
| 24 | 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. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 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 .) |
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. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 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. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| No | Overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .) |
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| 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 | Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line. Short the check connector terminal F/P to the body GND using a jumper wire. Turn the ignition switch to the ON position (Engine off). Is the fuel line pressure correct with the ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION .) Fuel line pressure
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Yes | Inspect the following PIDs:
(See PCM INSPECTION .) Inspect the PCM GND condition. |
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| 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 .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .) |
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