Dodge Durango (DN) 1998-2003 Service Manual » Engine » Diagnosis and testing »

Engine diagnosis-introduction. Service diagnosis-performance

Engine diagnosis-introduction

Engine diagnosis is helpful in determining the causes of malfunctions not detected and remedied by routine maintenance.

These malfunctions may be classified as either performance (e.g., engine idles rough and stalls) or mechanical (e.g., a strange noise).

Refer to the Service Diagnosis-Performance chart and the Service Diagnosis-Mechanical chart for possible causes and corrections of malfunctions. Refer to Group 14, Fuel System for the fuel system diagnosis.

Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that can not be isolated with the Service Diagnosis charts.

Information concerning additional tests and diagnosis is provided within the following diagnosis:

  • Cylinder Compression Pressure Test.
  • Cylinder Combustion Pressure Leakage Test.
  • Engine Cylinder Head Gasket Failure Diagnosis.
  • Intake Manifold Leakage Diagnosis.

Service diagnosis-performance

CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery

2. Corroded or loose battery connections.

3. Faulty starter.

4. Moisture on ignition wires and distributor cap.

5. Faulty ignition cables.

6. Faulty coil or control unit.

7. Incorrect spark plug gap.

8. Incorrect ignition timing

9. Dirt or water in fuel system.

10. Faulty fuel pump, relay or wiring.

 1. Charge or replace as necessary.

2. Clean and tighten battery connections. Apply a coat of light mineral grease to the terminals.

3. Refer to Group 8A, Battery/ Starter/ Charging System Diagnostics.

4. Wipe wires and cap clean and dry.

5. Replace as necessary.

6. Refer to Group 8D, Ignition System.

7. Refer to Group 8D, Ignition System.

8. Refer to Group 8D, Ignition System.

9. Clean system and replace fuel filter.

10. Refer to Group 14, Fuel System.
ENGINE STALLS OR ROUGH IDLE 1. Idle speed set to low.

2. Idle mixture to lean or to rich.

3. Vacuum leak.

4. Worn or burned distributor rotor.

5. Incorrect ignition wiring.

6. Faulty coil.

7. EGR valve leaking.

8. Incorrect cam timing.

 1. Refer to Group 14, Fuel System.

2. Refer to Group 14, Fuel System.

3. Inspect intake manifold and vacuum hoses, repair or replace as necessary.

4. Replace distributor rotor.

5. Install correct wiring.

6. Refer to Group 8D, Ignition System.

7. Refer to Group 25, Emissions Control System.

8. Refer to Valve Timing in this section.
ENGINE LOSS OF POWER 1. Incorrect ignition timing.

2. Worn or burned distributor rotor.

3. Worn distributor shaft.

4. Dirty or incorrectly gapped spark plugs.

5. Dirt or water in fuel system.

6. Faulty fuel pump.

7. Blown cylinder head gasket.

8. Low compression.

9. Burned, warped or pitted valves.

10. Plugged or restricted exhaust system.

11. Faulty ignition cables.

12. Faulty coil.

13. Incorrect cam timing.

 1. Refer to Group 8D, Ignition System.

2. Replace distributor rotor.

3. Refer to Group 8D, Ignition System.

4. Refer to Group 8D, Ignition System.

5. Clean system and replace fuel filter.

6. Refer to Group 14, Fuel System.

7. Replace cylinder head gasket.

8. Test compression, repair as necessary.

9. Replace as necessary

10. Inspect and replace as necessary.

11. Replace as necessary.

12. Refer to Group 8D, Ignition System.

13. Refer to Valve Timing in this section.
ENGINE MISSES ON ACCELERATION 1. Spark plugs dirty or incorrectly gapped.

2. Incorrect ignition timing.

3. Dirt in fuel system.

4. Burned, warped or pitted valves.

5. Faulty coil.

6. Incorrect cam timing.

 1. Refer to Group 8D, Ignition System.

2. Refer to Group 8D, Ignition System.

3. Clean fuel system.

4. Replcae as necessary

5. Refer to Group 8D, Ignition System.

6. Refer to Valve Timing in this section.
ENGINE MISSES AT HIGH SPEED 1. Spark plugs dirty or incorrectly gapped.

2. Worn Distributor Shaft.

3. Worn or burned distributor rotor.

4. Faulty coil.

5. Incorrect ignition timing.

6. Dirt or water in fuel system.

7. Incorrect cam timing.

 1. Refer to Group 8D, Ignition System.

2. Refer to Group 8D, Ignition System.

3. Replace distributor rotor.

4. Refer to Group 8D, Ignition System.

5. Refer to Group 8D, Ignition System.

6. Clean system and replace fuel filter.

7. Refer to Valve Timing in this section.

    « Previous

    Next Page »

    Dodge Durango (DN) 1998-2003 Service Manual

    Categories


    © 2017-2024 Copyright www.dodurango.net