Diagnostic Procedure
WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.
NO.19 EXHAUST SMOKE [BP, BP WITH TC] DIAGNOSTIC PROCEDURE
| STEP |
INSPECTION |
ACTION |
| 1 |
- What color is smoke coming from exhaust system?
|
Blue |
Burning oil is indicated.
Go to the next step. |
| White |
Water in combustion is indicated.
Go to Step 3. |
| Black |
Rich fuel mixture is indicated.
Go to Step 4. |
| 2 |
- Remove and shake PCV valve.
- Does PCV valve rattle?
|
Yes |
Inspect for following:
- Damaged valve guide, stems or valve seals
- Blocked oil drain passage in cylinder head
- Piston rings for not seated, seized or worn
- Damaged cylinder bore
- If other driveability symptoms are present, return to diagnostic index to service any additional symptoms.
|
| No |
Replace PCV valve. |
| 3 |
- Does cooling system hold pressure?
|
Yes |
Inspect for following:
- Cylinder head gasket leakage
- Intake manifold gasket leakage
- Engine block cracked or porous
- If other driveability symptoms are present, return to diagnostic index to service any additional symptoms.
|
| No |
Inspect for cause. |
| 4 |
- Inspect for following:
- ACL restriction
- Collapsed or restricted intake-air system
- Restricted fuel return line
- Are all items okay?
|
Yes |
Go to the next step. |
| No |
Service if necessary.
Repeat Step 5. |
| 5 |
- Connect WDS or equivalent to DLC-2.
- Turn ignition switch to ON.
- Retrieve any DTC.
- Is "PASSED" displayed?
|
Yes |
No DTC displayed:
|
| No |
DTC displayed:
- Go to appropriate DTC test.
|
| 6 |
- Install fuel pressure gauge between fuel filter and fuel distributor.
- Start engine and run it at idle.
- Measure fuel line pressure at idle.
- Is fuel line pressure correct at idle?
Fuel line pressure 370-420 kPa {3.7-4.3 kgf/cm2, 53-61 psi} |
Yes |
Go to the next step. |
| No |
Zero or low:
- Inspect FP circuit.
- Inspect for open FP relief valve.
- Inspect for fuel leakage inside pressure regulator.
- Inspect for clogged main fuel line.
- Inspect pulsation damper.
High:
- Inspect pressure regulator for high pressure cause.
- Inspect for clogged fuel return line.
|
| 7 |
- Is strong blue spark visible at each disconnected high-tension lead while cranking engine?
|
Yes |
Inspect spark plugs and CMP sensor. |
| No |
Inspect following:
- High-tension leads
- Ignition coil and connector
|
| 8 |
- Verify test results.
- If okay, return to diagnostic index to service any additional symptoms.
- If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
- If vehicle is repaired, troubleshooting completed.
- If vehicle is not repaired or additional diagnostic information is not available, replace PCM.
|