Simple & Relatively Easy to Check:
* Fuel System:
* Empty fuel tank: Sounds obvious, but it's the first thing to check.
* Fuel pump failure: Listen for the fuel pump whirring when you turn the key to the "on" position (but don't crank the engine). If you don't hear it, the pump might be dead.
* Clogged fuel filter: This restricts fuel flow to the engine.
* Bad fuel injectors: These spray fuel into the cylinders. A malfunctioning injector can cause the engine to stall or fail to start.
* Electrical System:
* Dead battery: Check the battery voltage with a multimeter.
* Loose or corroded battery cables: Clean the terminals and connections.
* Alternator failure: While this usually causes problems while driving, a failing alternator could cause a sudden stall if it's completely failed.
* Crankshaft Position Sensor (CKP) or Cam Position Sensor (CMP): These sensors tell the computer the engine's rotational position. A faulty sensor prevents the engine from starting or running.
* Ignition switch problems: This could be a wiring issue or a faulty switch itself.
* Ignition System:
* Distributor cap and rotor (if applicable): These wear out and can cause misfires leading to stalling (though less common on 1999 models).
* Spark plugs and wires: Check for wear, damage, or corrosion.
More Complex & Likely Requiring Professional Diagnosis:
* Engine Control Module (ECM) failure: The computer controlling the engine has failed.
* Internal engine failure: This could be anything from a broken timing chain/belt (resulting in valve damage), a catastrophic engine failure (rod knock, spun bearing), or other serious mechanical issue. This is less likely to be a *sudden* quit without prior warning signs, though possible in very rare circumstances.
* Overheating: While this usually causes gradual issues, a severe overheat could cause damage leading to immediate failure. Check the coolant level.
What to do:
1. Check the obvious: Fuel level, battery voltage, and connections.
2. Listen for the fuel pump: Turn the key to the "on" position (don't crank) and listen carefully.
3. Check for error codes: If your Durango has an OBD-II port, you can use a code reader to check for diagnostic trouble codes (DTCs). Auto parts stores often offer this service for free.
4. Have it towed to a mechanic: If you're not comfortable troubleshooting these issues, it's best to have a qualified mechanic diagnose the problem. The potential for more extensive damage warrants professional inspection. The sudden failure suggests something more serious than a simple fix might be at hand.
Without more information about the circumstances of the engine quitting (any warning signs beforehand, smoke, unusual noises), it's difficult to pinpoint the exact cause. The best course of action is a professional inspection.
