Fuel System:
* Fuel Pump: This is the most likely culprit. A failing fuel pump can't supply enough fuel under pressure, leading to symptoms of running out of gas, especially under load (acceleration). You'll need to check the fuel pressure. A fuel pressure gauge is necessary for this. You should check the pressure at the fuel rail. Compare your reading to the specifications for your 1988 F150 302.
* Fuel Pump Relay: Even if the pump is good, a bad relay might prevent it from getting power. A simple test involves swapping the relay with another (non-critical) relay to see if the problem follows the relay.
* Clogged Fuel Lines or Injectors: Although you changed the filter, there might still be debris clogging the lines or injectors. A fuel system cleaner might help, but if the problem persists, a professional cleaning or injector replacement might be needed.
* Fuel Pressure Regulator: This regulator maintains the correct fuel pressure in the system. A faulty regulator can cause low fuel pressure. This is another component that would require a fuel pressure gauge for diagnosis.
Ignition System:
* Distributor Cap and Rotor: These wear out over time and can cause misfires, leading to poor running. Inspect them for cracks, corrosion, or excessive wear. Replacement is relatively inexpensive.
* Spark Plugs and Wires: Worn or fouled spark plugs and cracked or corroded wires can prevent a good spark, leading to similar symptoms. Inspect and replace as needed.
* Ignition Coil: A weak or failing ignition coil can produce a weak spark. Testing this usually requires a specialized tool.
* TFI Module (Thick Film Ignition): This is the electronic ignition control module on your 1988 F-150 302. A failing TFI module can cause intermittent or complete failure of the ignition system. These can be prone to overheating.
Other Possibilities:
* EGR Valve: A stuck-open EGR valve can lean out the mixture, causing similar symptoms.
* Vacuum Leaks: Leaks in the vacuum lines can disrupt the fuel/air mixture. Inspect all vacuum lines for cracks or loose connections.
* Intake Manifold Gasket: A leak here can cause a lean mixture.
Troubleshooting Steps:
1. Start with the fuel pressure test. This is crucial. Low fuel pressure points directly to the fuel system.
2. Inspect the easy-to-check components: distributor cap, rotor, spark plugs, wires, and vacuum lines.
3. Check fuel pump relay.
4. If fuel pressure is good, then focus on the ignition system.
If you are not comfortable working on your vehicle's fuel and ignition systems, it's best to take it to a qualified mechanic. They have the tools and expertise to diagnose the problem accurately and efficiently. Fuel system issues can be dangerous if not handled correctly.
