* Verify the new fuel pump is working: This is crucial. You need to confirm the new pump is actually receiving power and pumping fuel. This often involves:
* Checking the fuel pump relay: A faulty relay can prevent power from reaching the pump. Locate the relay (usually in the fuse box under the hood or in the cabin) and try swapping it with a known good one of the same amperage.
* Listening for the pump: Turn the ignition key to the "ON" position (don't crank the engine). You should hear a brief humming sound from the fuel pump as it primes. If you don't hear it, the pump might not be getting power or is defective.
* Checking for fuel pressure: This requires a fuel pressure gauge. The gauge is connected to the fuel rail, and you should see pressure build up when the ignition is turned on. The exact pressure specification is in your car's repair manual. Low or no pressure indicates a problem with the pump, its wiring, the fuel filter, or the fuel pressure regulator.
* Checking the fuel pump fuse: A blown fuse will also prevent the pump from working. Check the fuse box for a blown fuse related to the fuel pump.
* Fuel filter: A clogged fuel filter can restrict fuel flow, even with a new pump. Replace the fuel filter – it's a relatively inexpensive and easy fix.
* Wiring: Check all wiring connections to the fuel pump. Ensure they are securely connected and not damaged or corroded. A faulty wire can interrupt the power supply.
* Fuel pump control module (PCM): In some vehicles, a control module manages the fuel pump. A faulty PCM can prevent the pump from activating. This is less likely but possible. Diagnostics with a scan tool would be needed to check the PCM.
* Immobilizer system: Some cars have an immobilizer system that prevents the engine from starting if it doesn't recognize the car key. Make sure you're using the correct key.
* Crankshaft position sensor (CKP sensor): A faulty CKP sensor won't allow the engine to start even if there's fuel. This sensor tells the computer the position of the engine.
* Camshaft position sensor (CMP sensor): Similar to the CKP sensor, a faulty CMP sensor can prevent the engine from starting.
Important Note: If you're not comfortable working on your car's fuel system, it's best to take it to a qualified mechanic. Working with fuel can be dangerous. Incorrectly working on the fuel system could cause a fire or explosion.
