## Fuel and Emissions Systems

#### Symptom Troubleshooting Index (cont'd)

11-12

Symptom | Diagnostic Procedure | Also check for
Misfire or rough |

1. Intake System.

   (Intake manifold, air cleaner, MAF sensor)

2. ECM (ECT Sensor, ECM)
3. Vehicle Speed Sensor
4. Exhaust System.

   (EGR system, Turbocharger, Vacuum system)

5. BARO Sensor
6. Injector

- Low Compression
- Engine Mechanical

Fail emission test |

1. Intake System.

   (Intake manifold, air cleaner, MAF sensor)

2. Oil viscosity
3. BARO Sensor
4. Exhaust System.

   (EGR system, Turbocharger, Vacuum system)

5. Fuel Injection System.

   (Injector, Supply Pump, Common Rail)

6. Catalyst Converter.

- Contaminated Fuel
- Engine Oil Quality

Loss of power |

1. Fuel filter, Fuel Line, Fuel, Fuel Condition.
2. Throttle System.

   (AP Sensor, Throttle cable)

3. Intake System.

   (Intake manifold, air cleaner, MAF sensor)

4. Fuel Injection System.

   (Injector, Supply Pump, Common Rail with RP sensor)

5. Exhaust System.

   (EGR system, Turbocharger, Vacuum system)

6. BARO Sensor
7. Vehicle Speed Sensor
8. Air Condition System

- Low Compression
- Engine Mechanical
- Chassis Parts Error

Hesitation/Surging |

1. Fuel filter, Fuel Line, Fuel, Fuel Condition.
2. Exhaust System.

   (EGR system, Turbocharger, Vacuum system)

3. Intake System.

   (Intake system, filter)

4. Fuel Injection System.

   (Injector, Supply Pump, Common Rail)

5. Vehicle Speed Sensor
6. Air Condition System

- Engine Mechanical
- Chassis Parts Error

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