* Fuel Pump Relay: While fuses are good, the relay itself could be faulty. The relay acts as a switch, so even if the fuse is intact, the relay might not be sending power to the fuel pump. Try swapping the relay with another of the same amperage (check your owner's manual for locations and amperage).
* Wiring Issues: Check the wiring from the fuel pump relay to the fuel pump itself. Look for broken wires, corrosion, or loose connections. This is crucial. A simple break in a wire can prevent the pump from functioning.
* Fuel Pump Pressure: You need to test the fuel pressure at the fuel rail. A pressure gauge is needed for this – borrow or rent one from an auto parts store. This directly tells you if the pump is delivering sufficient pressure. Low pressure indicates a problem even if the pump *seems* to be running.
* Fuel Pump itself (despite replacement): There's a chance the *new* fuel pump is faulty. Though unlikely, it's possible to get a defective replacement. Check the return policy.
* Clogged Fuel Injector(s): Even with a new filter, individual injectors could be clogged. This requires specialized tools and cleaning procedures, sometimes involving an injector cleaner or professional cleaning service.
* Fuel Pressure Regulator: This regulator maintains proper fuel pressure. A faulty regulator can prevent sufficient fuel from reaching the engine.
* Crankshaft Position Sensor (CKP) or Camshaft Position Sensor (CMP): These sensors tell the engine's computer the position of the crankshaft and camshaft. If either is faulty, the engine won't start even if fuel is present because the computer won't know when to inject fuel. These can affect fuel delivery indirectly.
Troubleshooting Steps:
1. Fuel Pump Relay Test (Most Likely): This is the easiest and cheapest test to perform first.
2. Visual Inspection of Wiring: Carefully inspect all wiring related to the fuel system.
3. Fuel Pressure Test: This is the most definitive way to check if the fuel pump is working correctly.
4. Check for error codes: Use an OBD-II scanner to check for any diagnostic trouble codes (DTCs). These codes can pinpoint the problem.
Important Note: Working with fuel systems involves flammable liquids. Take necessary precautions, such as working in a well-ventilated area and avoiding open flames. If you're not comfortable performing these tests yourself, take the vehicle to a qualified mechanic.
