High-Probability Issues:
* Broken or Loose Ignition System Components: The impact could have dislodged or broken wires in the ignition system (distributor cap, rotor, ignition coil, wires to the spark plugs). Check for:
* Loose or broken wires: Carefully inspect all wires leading to and from the distributor cap, ignition coil, and spark plugs. Look for cracks, frayed ends, or loose connections.
* Damaged distributor cap and rotor: Look for cracks or burns on the cap and rotor. Even minor damage can disrupt the spark.
* Failed ignition coil: A cracked or internally damaged coil won't produce the necessary high voltage. This requires a multimeter to test.
* Broken or Damaged Crank Position Sensor (CPS): The CPS tells the computer the engine's rotational position, essential for firing the spark plugs at the right time. A bump could easily damage it. This is a common failure point on older Jeeps. It will need to be tested with a multimeter or replaced.
* Fuel Pump Issues: While less likely to be directly caused by the bump, the impact *could* have damaged the fuel pump's wiring, fuel lines, or even the pump itself. Check:
* Fuel pump relay: Make sure it's clicking when the ignition is turned on.
* Fuel pressure: This requires a fuel pressure gauge to test. Low or no fuel pressure indicates a problem with the pump, lines, or filter.
* Broken or Damaged Wiring Harness: A bump can cause wires to short, break, or become disconnected within the engine bay's wiring harness. This is difficult to diagnose without a wiring diagram and a multimeter.
Less-Likely (but Possible) Issues:
* Broken or loose ground straps: A good ground connection is crucial. A loose or broken ground strap can prevent the engine from starting.
* Damaged components in the fuel system: A damaged fuel injector, filter, or fuel line could be the cause, although less likely from a bump.
Troubleshooting Steps:
1. Visual Inspection: Start with a thorough visual inspection of the engine bay. Look for any obvious signs of damage, loose wires, or broken components.
2. Check for Spark: Remove a spark plug wire, ground it to the engine block, and crank the engine. You should see a spark. If not, the problem lies within the ignition system.
3. Check for Fuel: Remove a fuel line and crank the engine to see if fuel is being delivered to the fuel rail. If no fuel, check the pump and relay.
4. Listen for the Fuel Pump: When you turn the key to the "on" position (but don't crank), you should hear the fuel pump prime for a second or two. If you don't hear it, that's a potential problem.
5. Check all fuses and relays: Look at the fuse box under the hood and the fuse panel inside the vehicle. A blown fuse could be the culprit.
6. Use a Multimeter: This is essential for testing the CPS, ignition coil, and checking for power at various points in the ignition and fuel systems.
Important Note: If you're not comfortable working on your vehicle's electrical system, it's best to take it to a qualified mechanic. Attempting repairs without the necessary knowledge can lead to further damage. The crank position sensor is a relatively common and easy replacement, but other issues may be more complex.
