* Fuel System Problems: Even though you're using starter fluid, the underlying fuel system needs investigation.
* Fuel Pump: The fuel pump might be faulty, not providing enough pressure to the injectors. Listen closely for the fuel pump's hum when the key is turned to the "on" position (but not cranking). A weak or absent hum indicates a problem.
* Fuel Filter: A clogged fuel filter can restrict fuel flow. Replace it.
* Fuel Injectors: These could be clogged, malfunctioning, or have low pressure. This requires professional diagnosis and likely testing/cleaning/replacement.
* High-Pressure Oil Rail (HPOP): The 7.3 Power Stroke relies on the HPOP to pressurize the fuel injectors. A failing HPOP will prevent starting, even with starter fluid. This is a common failure point on these engines.
* Fuel Pressure Regulator: A faulty regulator could lead to incorrect fuel pressure.
* Ignition System Problems: Starter fluid bypasses the ignition system's spark delivery, but it's still a consideration:
* Glow Plugs: While glow plugs are primarily for cold starts, faulty glow plugs *can* contribute to no-start issues even when warm.
* Ignition Switch: A bad ignition switch can prevent power from reaching the necessary components.
* Wiring Harness: Damaged or corroded wiring in the ignition system can interrupt the electrical flow.
* Other Issues:
* PCM (Powertrain Control Module): A faulty PCM can prevent the engine from starting by not sending the correct signals. This would require professional diagnostics.
* Security System: If your truck has an aftermarket alarm or immobilizer, it could be preventing the engine from starting.
Troubleshooting Steps:
1. Battery and Connections: Make absolutely sure the battery is fully charged and the terminals are clean and tight. A weak battery will crank slowly, but even that would likely not prevent starter fluid from working.
2. Fuel Pump: Listen for the fuel pump hum.
3. Fuel Filter: Replace the fuel filter—it's relatively inexpensive and a common maintenance item.
4. Check Engine Codes: Use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs) stored in the PCM. This might offer clues. For a 1995 model, you may need an older scanner compatible with OBD-I.
5. Visual Inspection: Look for any obvious signs of damage to wiring, loose connections, or fuel leaks.
Recommendation:
Given the complexity of the 7.3 Power Stroke fuel system and the fact that starter fluid isn't helping, it's highly recommended to take your truck to a mechanic specializing in diesel engines. Trying to diagnose and repair these issues without experience can be costly and potentially damaging. A professional diagnosis will be much more efficient and save you time and money in the long run.
