1. Fuel Supply Issues:
* Empty Tank: The obvious first check. Seriously, make sure you have gas!
* Fuel Pump Failure: This is a very common cause. The pump may be weak, failing to build pressure, or completely dead. You can often hear the pump prime when you turn the ignition on – listen carefully. If you don't hear it, it's a strong suspect.
* Clogged Fuel Filter: A clogged filter restricts fuel flow. It's relatively inexpensive and easy to replace, so it's a good preventative measure to replace it regularly.
* Fuel Line Restrictions: Kinks, rust, or debris in the fuel lines can impede fuel flow. Check the lines visually for damage.
* Fuel Tank Issues: Possible issues include a clogged fuel tank pickup tube (the tube that sucks fuel from the tank), debris in the tank, or a collapsed tank.
2. TBI System Issues:
* Fuel Pressure Regulator (FPR): A faulty FPR may not be regulating pressure correctly, leading to either too little or too much fuel pressure. Testing the fuel pressure is crucial here.
* Throttle Body Injector(s): The injectors could be clogged, faulty, or not receiving the correct electrical signal. Testing injector operation and spray pattern is necessary.
* Throttle Position Sensor (TPS): A faulty TPS can disrupt the fuel delivery system as it provides crucial engine load information.
* Computer (ECM): The ECM controls the fuel injection system. A faulty ECM can cause various problems, including no fuel delivery.
* Wiring and Connectors: Look for corrosion, broken wires, or loose connectors in the fuel system wiring harness. Pay close attention to the connectors at the TBI unit itself and the fuel pump relay.
3. Other Possibilities:
* Ignition Switch: A malfunctioning ignition switch might not be powering the fuel pump relay.
* Fuel Pump Relay: A bad relay will prevent the fuel pump from receiving power.
Troubleshooting Steps:
1. Check for Fuel Pressure: This is the most important step. You'll need a fuel pressure gauge to test the pressure at the TBI unit. This will quickly help pinpoint whether the problem lies in the fuel supply or the injection system.
2. Listen for the Fuel Pump: Turn the ignition key to the "ON" position (don't crank the engine). You should hear the fuel pump run for a few seconds. If you don't hear it, suspect a pump, relay, or wiring problem.
3. Visual Inspection: Inspect the fuel lines, fuel filter, and TBI unit for any obvious damage or leaks.
4. Check the Fuel Pump Relay: You can swap the fuel pump relay with another relay of the same amperage to see if that resolves the issue. (Always consult your owner's manual for relay location and identification.)
5. Test the Fuel Injectors: You might need a multimeter or a dedicated injector tester for this.
Important Note: Working with fuel systems involves potential fire hazards. Be cautious, work in a well-ventilated area, and disconnect the negative battery terminal before starting any work. If you are not comfortable working on your fuel system, take your car to a qualified mechanic.
