* Fuel Pump: A failing fuel pump might be intermittently unable to deliver sufficient fuel pressure. This is common as they age. The symptoms often include sputtering, hesitation, or complete stalling, especially under load or when the tank is low. A fuel pressure gauge test is crucial here.
* Fuel Filter: A clogged fuel filter restricts fuel flow, leading to similar symptoms as a failing fuel pump. This is a relatively inexpensive and easy component to replace.
* Pick-up Tube (in the tank): If the pick-up tube inside the fuel tank is clogged or damaged, the pump can't draw fuel effectively. This is more likely if the problem is worse when the tank is near empty.
* Fuel Injectors: Clogged or faulty fuel injectors can cause intermittent fuel delivery. One or more injectors might be sticking open or closed, leading to inconsistent performance. Injector cleaning or replacement might be needed.
* Ignition System: While seemingly unrelated to fuel, problems in the ignition system (distributor cap, rotor, wires, coil, crankshaft position sensor) can cause misfires that *feel* like fuel starvation. A misfire can starve the engine of power, mimicking a fuel problem. A diagnostic scan tool can often pinpoint misfires.
* Throttle Position Sensor (TPS): A malfunctioning TPS can send incorrect information to the engine control unit (ECU), leading to improper fuel delivery.
* Mass Airflow Sensor (MAF): Similar to the TPS, a faulty MAF sensor provides inaccurate air flow data to the ECU, which then adjusts fuel delivery incorrectly. This often leads to a rich or lean condition, causing poor performance or stalling.
* Computer/ECU: In rare cases, the ECU itself could be faulty, although this is less common than the other issues. A diagnostic scan can help reveal ECU-related problems.
* Wiring Issues: Loose, corroded, or damaged wiring in the fuel system or ignition system can cause intermittent problems.
Troubleshooting Steps:
1. Start with the simplest and cheapest: Check the fuel filter first. It's easy to replace and a frequent culprit.
2. Fuel Pressure Test: Use a fuel pressure gauge to measure the fuel pressure. This is essential to diagnose fuel pump and related problems.
3. Visual Inspection: Inspect fuel lines and connections for leaks or damage.
4. Diagnostic Scan: Use an OBD-II scanner to read trouble codes from the ECU. This can often point directly to the problem.
5. Check Ignition System: Inspect the distributor cap, rotor, spark plug wires, and coil for wear or damage.
Since this is an older vehicle, it's possible that multiple components are contributing to the problem. Systematic troubleshooting is key. If you're not comfortable working on your car yourself, take it to a qualified mechanic for diagnosis and repair.
