* Fuel Pump Relay: Even with a new pump, a faulty relay might not be sending power to the pump correctly. Check the relay and try swapping it with a known good one of the same amperage (verify amperage before swapping!).
* Fuel Pump Fuse: A blown fuse will prevent power from reaching the pump. Check the fuse box for a blown fuse related to the fuel pump circuit.
* Wiring Issues: There might be a break or short in the wiring between the fuel pump relay/fuse and the pump itself. Inspect the wiring harness carefully for any damage, corrosion, or loose connections. This is particularly important near the tank where the wiring is vulnerable.
* Fuel Filter: A clogged fuel filter will prevent fuel from flowing even if the pump is working correctly. Replace the fuel filter; it's a cheap and easy check.
* Fuel Pressure Regulator: This regulates the fuel pressure in the system. A faulty regulator might not allow sufficient fuel to reach the engine even if the pump is delivering fuel.
* Incorrect Fuel Pump Installation: It's possible the new fuel pump wasn't installed correctly. Double-check all connections and ensure it's seated properly. A common mistake is improper orientation or a leaking seal.
* Inhibitor Switch (GM vehicles sometimes have these): Some GM vehicles have an inertia switch that cuts off fuel delivery in a collision. Check to see if this has been triggered.
* Crankshaft Position Sensor (CPS): Though less likely directly related to the fuel pump itself, a bad CPS can prevent the engine from starting.
Troubleshooting Steps:
1. Check the fuses and relays: This is the easiest and quickest step.
2. Replace the fuel filter: This is inexpensive and often overlooked.
3. Inspect the wiring: Look for any visual damage or loose connections.
4. Check fuel pressure: Use a fuel pressure gauge to measure the pressure at the fuel rail. This will tell you definitively if the pump is delivering fuel at the correct pressure. This requires a special tool.
5. Verify fuel pump installation: If you replaced it yourself, double-check the installation. A professional mechanic can confirm.
Since starter fluid works, it confirms the engine's ability to ignite. The problem lies solely within the fuel delivery system from the tank to the engine. Systematic checking of the above points will likely pinpoint the issue. If you're not comfortable with these checks, take it to a mechanic. A misdiagnosed fuel delivery problem can lead to further engine damage.
