Fuel System Issues:
* Fuel pump: A failing fuel pump might be able to supply fuel for a short distance but then struggle to keep up, leading to fuel starvation. This is a common cause of stalling.
* Fuel filter: A clogged fuel filter restricts fuel flow, similar to a failing fuel pump.
* Fuel pressure regulator: A faulty regulator might not maintain proper fuel pressure, causing inconsistent fuel delivery.
* Fuel injectors: Clogged or faulty injectors can prevent proper fuel atomization and delivery to the engine.
Ignition System Problems:
* Ignition coil: A failing ignition coil can lose its ability to generate the high voltage needed to ignite the fuel-air mixture in the cylinders. This often manifests as stalling or misfiring.
* Distributor cap and rotor (if applicable): Cracks or corrosion in these components can lead to poor spark delivery. (This is less likely on a 1996, depending on engine type but still possible).
* Ignition wires: Worn or damaged ignition wires can cause misfires and stalling.
* Crankshaft Position Sensor (CKP): This sensor tells the computer the engine's rotational speed. A faulty one can lead to all sorts of problems, including stalling.
Cooling System Issues:
* Overheating: While less likely to cause a stall after only 5 miles, a severely overheating engine can cause the computer to shut down the engine as a safety precaution. Check your coolant level and look for any signs of overheating (steam, etc.).
Other Potential Causes:
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle position. A faulty TPS can cause erratic idle and stalling.
* Mass Airflow Sensor (MAF): This sensor measures the amount of air entering the engine. A dirty or faulty MAF can cause poor fuel mixture and stalling.
* Computer/PCM Issues: A failing PCM (Powertrain Control Module) can cause a wide range of problems, including stalling. This is less likely but possible.
* Vacuum Leaks: Leaks in the vacuum system can disrupt the engine's operation and cause stalling.
Troubleshooting Steps:
1. Check the obvious: Start with the basics. Check your engine oil, coolant, and battery levels.
2. Listen for unusual noises: Is there any unusual clicking, knocking, or whirring while driving?
3. Check for error codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in the PCM. This can provide valuable clues.
4. Start with the fuel system: A mechanic would likely start by checking fuel pressure and inspecting the fuel filter and pump.
5. Consider professional help: Diagnosing a stalling problem can be complex. It's often best to take your truck to a qualified mechanic who has experience with older vehicles. They have the tools and expertise to accurately diagnose and repair the issue.
Don't continue driving the truck extensively while it's exhibiting this problem, as you could cause further damage. Getting it towed or having it checked out is recommended.
