* Crankshaft Position Sensor (CKP): This sensor tells the car's computer the position of the crankshaft. If it's faulty, the computer might not send the signal to keep the fuel pump running *after* the initial prime.
* Cam Position Sensor (CMP): Similar to the CKP, a faulty CMP can prevent the computer from properly sequencing fuel delivery after the initial pump prime.
* Fuel Pump Relay: This relay controls the power to the fuel pump. It might be failing intermittently, providing power for the initial prime but not consistently afterwards.
* Fuel Pump itself (less likely): While less probable given your description (the pump *does* run initially), a weak or failing fuel pump could be struggling to maintain pressure after the initial burst.
* Computer/ECU Problem: In rare cases, a problem with the car's computer (ECU) could be causing the issue. This is less likely than the other problems listed.
* Wiring Issues: A short, corroded connection, or damaged wiring in the fuel pump circuit can interrupt power.
Troubleshooting Steps:
1. Check the fuel pump relay: Locate the fuel pump relay (consult your car's repair manual), and try swapping it with another relay of the same amperage (if possible). This is a quick and easy test.
2. Listen carefully: When you try to start the car, can you *hear* the fuel pump running after the initial prime (a brief whirring sound)? If not, this points to a relay, sensor, or wiring problem.
3. Check fuel pressure: This requires a fuel pressure gauge. You need to check the fuel pressure while cranking the engine to see if it's maintaining pressure. This is a more involved test that may require professional tools.
4. Have the codes scanned: Use an OBD-II scanner to check for any diagnostic trouble codes (DTCs) stored in the car's computer. This will often point directly to the faulty component.
Important Note: Working with fuel systems can be dangerous. If you are not comfortable performing these checks yourself, take your car to a qualified mechanic for diagnosis and repair.
