1. Fuel System Issues (Beyond Just the Low Fuel):
* Fuel Pump: Even with fuel in the tank, a weak or failed fuel pump won't deliver it to the engine. Listen carefully near the fuel tank (usually in the back of the car) when you turn the key to the "on" position (but don't crank). You should hear a brief whirring sound from the fuel pump. If you don't, that's a strong suspect.
* Fuel Filter: A clogged fuel filter can restrict fuel flow. This is less likely immediately after running out of gas, but possible if there was debris in the tank.
* Fuel Pressure: A mechanic can test the fuel pressure to see if the pump is delivering adequate pressure. This requires special tools.
2. Ignition System:
* Battery: A weak battery can fail to provide enough power to crank the engine, even if there's plenty of fuel. Check the battery terminals for corrosion and try jump-starting the car.
* Starter: The starter motor might be faulty. If you turn the key and hear absolutely nothing (no clicking, whirring, etc.), the starter could be at fault.
* Ignition Switch: Though less likely, the ignition switch itself could be malfunctioning.
* Distributor (if applicable): Older vehicles like some 1999 models might have a distributor. Issues like a bad cap or rotor could cause starting problems.
3. Other Possibilities:
* Security System: Some cars have immobilizer systems that prevent starting if they detect a problem. Check your owner's manual for details about your car's security system.
* Sensors: A variety of sensors (crankshaft position sensor, camshaft position sensor, etc.) can prevent starting if faulty. These require diagnostic tools to test.
* Fuel Injectors: While less likely, clogged or faulty fuel injectors could also be a culprit.
What to Do Now:
1. Jump Start (if possible): Try jump-starting the car to rule out a weak battery.
2. Listen for the Fuel Pump: As mentioned above, listen carefully for the whirring sound when you turn the key to "on".
3. Check the Battery Terminals: Clean any corrosion from the battery terminals.
4. Call a Mechanic or Roadside Assistance: Given the multiple possibilities, it's best to get professional help. They have the tools and expertise to diagnose the problem accurately.
Don't keep cranking the engine repeatedly if it doesn't start. This can further drain the battery.
