Dodge dakota 2002 Service Manual page 1338

DR
ENGINE - 4.7L
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION
ENGINE WILL NOT START
ENGINE STALLS OR ROUGH IDLE
1. ENGINE LOSS OF POWER
POSSIBLE CAUSE
1. Weak battery
2. Corroded or loose battery
connections.
3. Faulty starter.
4. Faulty coil or control unit.
5. Incorrect spark plug gap.
6. Dirt or water in fuel system.
7. Faulty fuel pump, relay or wiring.
1. Idle speed set to low.
2. Idle mixture too lean or too rich.
3. Vacuum leak.
4. Faulty coil.
5. Incorrect engine timing.
1. Dirty or incorrectly gapped spark
plugs.
2. Dirt or water in fuel system.
3. Faulty fuel pump.
4. Blown cylinder head gasket.
ENGINE - 4.7L
CORRECTION
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 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
6. Clean system and replace fuel
filter.
7. Repair or replace as necessary.
1. (Refer to 14 - FUEL SYSTEM/
FUEL INJECTION/IDLE AIR
CONTROL MOTOR - REMOVAL).
2. Refer to Powertrain Diagnosis
Information.
3. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD
PROCEDURE).
1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
2. Clean system and replace fuel
filter.
3. (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/FUEL PUMP -
DIAGNOSIS AND TESTING).
4. Replace cylinder head gasket.
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