Fuel Supply System:
* Low Fuel: The most obvious – check your fuel tank level.
* Fuel Filter: A clogged fuel filter restricts fuel flow. Replace it if it's dirty or old.
* Fuel Pump (Lift Pump): This pump draws fuel from the tank. It might be failing or have a low-pressure issue. You might hear a weak whirring sound if it's struggling.
* Fuel Pump Relay: A faulty relay can prevent the pump from powering on.
* Fuel Lines: Check for cracks, kinks, or blockages in the fuel lines running from the tank to the engine. Look for leaks as well.
* Water in Fuel: Water in the fuel can clog filters and damage injectors. Use a fuel system cleaner and potentially drain the tank.
* Fuel Tank Issues: Problems with the fuel tank itself, such as a blockage in the pickup tube, can prevent fuel from reaching the pump.
High-Pressure Fuel System (HPFP):
* High-Pressure Fuel Pump (HPFP): This pump pressurizes the fuel for injection. Failure is a common cause of no fuel at the injectors. These are expensive to replace.
* HPFP Wiring/Connector: Check the wiring and connector to the HPFP for damage or corrosion.
* Fuel Pressure Regulator: This regulates fuel pressure in the high-pressure system. A faulty regulator can cause low pressure or prevent fuel from reaching the injectors.
* Fuel Injectors: While unlikely to be the sole cause of *no* fuel reaching injectors (they'd likely receive some), a completely clogged injector could cause a pressure issue that effects other injectors. Usually, this manifests as poor running rather than a complete shutdown.
Other Potential Causes:
* ECM/PCM (Engine Control Module/Powertrain Control Module): The computer controls the entire fuel system. A faulty ECM can prevent fuel delivery. This requires diagnostic tools to check.
* Wiring Harnesses: Look for damaged or corroded wiring harnesses throughout the fuel system.
* Fuel Pressure Sensor: An inaccurate reading from this sensor can cause the ECM to adjust fuel delivery incorrectly.
* Security System: In rare cases, a problem with the vehicle's security system can prevent the engine from starting and thus prevent fuel delivery.
Troubleshooting Steps (In Order):
1. Check the fuel level.
2. Check the fuel filter.
3. Listen for the fuel pump: Turn the key to the "on" position (without starting the engine) and listen for the fuel pump's whirring sound near the fuel tank.
4. Visually inspect fuel lines for leaks or damage.
5. Consider using a fuel pressure gauge to measure fuel pressure at various points in the system (requires specific adapters and knowledge).
Important Considerations:
* Professional Diagnosis: Unless you have significant mechanical experience with diesel fuel systems, professional help is highly recommended. Incorrect diagnosis or repair can lead to significant damage and expense.
* Diagnostic Tools: A scan tool capable of reading codes from the ECM is essential for accurate diagnosis. Some problems will not trigger any engine codes.
* Safety: Diesel fuel is flammable. Take appropriate safety precautions when working on the fuel system.
Don't attempt complex repairs without the proper knowledge and tools. The cost of a misdiagnosis and subsequent repairs far outweighs the cost of professional help.
