* Fuel System Issues:
* Empty or low fuel: The most obvious, but often overlooked.
* Fuel pump failure: The pump might be malfunctioning, not delivering enough fuel, or completely dead.
* Clogged fuel filter: A clogged filter restricts fuel flow to the engine.
* Fuel injectors problems: Injectors might be clogged, malfunctioning, or not receiving the correct signal.
* Fuel pressure regulator issues: Incorrect fuel pressure prevents proper combustion.
* Ignition System Problems:
* Spark plug issues: Worn, fouled, or damaged spark plugs prevent the spark needed for combustion. Spark plug wires can also be faulty.
* Ignition coil problems: The coil provides the high voltage to the spark plugs; a faulty coil will prevent sparking in one or more cylinders.
* Crankshaft position sensor (CKP) or camshaft position sensor (CMP) failure: These sensors tell the computer the engine's position, and if they're faulty, the computer won't send the signal to fire the spark plugs.
* Distributor cap and rotor (if applicable): Older Explorers might have a distributor; worn parts can cause ignition problems.
* Ignition control module (ICM): This module controls the ignition system; a failure can prevent the engine from starting.
* Computer/Electrical Issues:
* PCM (Powertrain Control Module) problems: The computer controls many aspects of the engine; a faulty PCM can cause a multitude of issues, including no start. This often requires professional diagnosis.
* Faulty wiring or connectors: Damaged or corroded wiring can interrupt the electrical signals needed for starting.
* Security system issues: The vehicle's anti-theft system might be preventing the engine from starting.
* Other Potential Causes:
* Low compression: Worn piston rings or valve problems can lead to insufficient compression, preventing the engine from starting. This usually leads to other symptoms as well, like difficulty running once started.
Troubleshooting Steps (in general order of ease):
1. Check the fuel level: The simplest check.
2. Listen for the fuel pump: Turn the key to the "on" position (without cranking). You should hear a brief whirring sound from the fuel pump. If not, it might be faulty.
3. Check the spark plugs (if accessible): Remove a spark plug and check for spark while cranking the engine. A spark tester can help.
4. Check for any diagnostic trouble codes (DTCs): Use an OBD-II scanner to read any codes stored in the PCM. These codes can provide valuable clues.
If you're not comfortable performing these checks yourself, take your Ford Explorer to a qualified mechanic for diagnosis and repair. Trying to troubleshoot without the proper tools and knowledge can lead to further damage.
