DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE


CONDITION
  		 POSSIBLE CAUSE
  		 CORRECTION
  
ENGINE WILL NOT START
  		 1. Weak battery
  		 1. Charge or replace as necessary.
  
2. Corroded or loose battery connections.
  		 2. Clean and tighten battery connections. Apply a coat of light mineral grease to the terminals.
  		  
3. Faulty starter.
  		 3. (Refer to 8 - ELECTRICAL/STARTING - DIAGNOSIS AND TESTING).
  		  
4. Faulty coil or control unit.
  		 4. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/IGNITION COIL - REMOVAL).
  		  
5. Incorrect spark plug gap.
  		 5. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/SPARK PLUG - CLEANING).
  		  
6. Dirt or water in fuel system.
  		 6. Clean system and replace fuel filter.
  		  
7. Faulty fuel pump, relay or wiring.
  		 7. Repair or replace as necessary.
  		  
ENGINE STALLS OR ROUGH IDLE
  		 1. Idle speed set to low.
  		 1. (Refer to 14 - FUEL SYSTEM/FUEL INJECTION/IDLE AIR CONTROL MOTOR - REMOVAL).
  
2. Idle mixture too lean or too rich.
  		 2. Refer to Powertrain Diagnosis Information.
  		  
3. Vacuum leak.
  		 3. Inspect intake manifold and vacuum hoses, repair or replace as necessary.
  		  
4. Faulty coil.
  		 4. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/IGNITION COIL - REMOVAL).
  		  
5. Incorrect engine timing.
  		 5. (Refer to 9 - ENGINE/VALVE TIMING - STANDARD PROCEDURE).
  		  
ENGINE LOSS OF POWER
  		 1. Dirty or incorrectly gapped spark plugs.
  		 1. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/SPARK PLUG - CLEANING).
  
2. Dirt or water in fuel system.
  		 2. Clean system and replace fuel filter.
  		  
3. Faulty fuel pump.
  		 3. Refer to the Appropriate Diagnostic Information
  		  
4. Blown cylinder head gasket.
  		 4. Replace cylinder head gasket.
  		  
5. Low compression.
  		 5. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
  		  
6. Burned, warped or pitted valves.
  		 6. Replace as necessary.
  		  
7. Plugged or restricted exhaust system.
  		 7. Inspect and replace as necessary.
  		  
8. Faulty coil.
  		 8. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/IGNITION COIL - REMOVAL).
  		  
ENGINE MISSES ON ACCELERATION
  		 1. Spark plugs dirty or incorrectly gapped.
  		 1. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/SPARK PLUG - CLEANING).
  
2. Dirt in fuel system.
  		 2. Clean fuel system.
  		  
3. Burned, warped or pitted valves.
  		 3. Replcae as necessary.
  		  
4. Faulty coil.
  		 4. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/IGNITION COIL - REMOVAL).
  		  
ENGINE MISSES AT HIGH SPEED
  		 1. Spark plugs dirty or incorrectly gapped.
  		 1. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/SPARK PLUG - CLEANING).
  
2. Faulty coil.
  		 2. (Refer to 8 - ELECTRICAL/IGNITION CONTROL/IGNITION COIL - REMOVAL).
  		  
3. Dirt or water in fuel system.
  		 3. Clean system and replace fuel filter.