1. Verify the Fuel Pump is Working
* Visual Inspection: Make sure the fuel pump is connected properly and there are no visible leaks.
* Listen for the Pump: Turn the ignition key to the "on" position (not starting the engine) and listen carefully for the fuel pump to hum. You should hear a faint buzzing sound for a few seconds. If you don't, there might be an electrical problem with the pump or its wiring.
* Test the Pump: If you have a fuel pressure gauge, connect it to the fuel line at the pump output. Turn the key on and check for pressure. A good fuel pump should deliver around 3-5 PSI.
2. Check the Fuel Lines
* Leaks and Clogs: Carefully inspect all fuel lines for leaks, cracks, or blockages. Look for any signs of fuel dripping or pooling. If the fuel lines are old and brittle, they could be restricting fuel flow.
* Fuel Filter: The fuel filter is often located near the fuel pump or carburetor. It can become clogged over time, restricting fuel flow. Replace the filter if it's old or dirty.
3. Inspect the Carburetor
* Clean and Adjust: The carburetor is where fuel and air mix before entering the engine. Dirt, debris, or a stuck float can prevent fuel from reaching the engine. Consider removing and cleaning the carburetor, or at least the float bowl, to make sure the float is moving freely and the jets are clear.
4. Check the Fuel Tank and Vent
* Empty Tank?: Make sure your fuel tank isn't empty.
* Vent Obstruction: A clogged vent in the fuel tank can create a vacuum, preventing fuel flow. Check the vent hose for blockages and ensure it's open to the atmosphere.
5. Electrical System Check
* Wiring: Verify all connections between the fuel pump, ignition, and carburetor are tight and secure. Look for corrosion or damaged wiring.
* Fuse: Make sure the fuse for the fuel pump is not blown.
Troubleshooting Tips:
* Start with the basics: Ensure you have a full fuel tank and that the key is in the "on" position.
* Listen closely: Pay attention to any sounds that might indicate a problem with the fuel system (e.g., a weak fuel pump hum, hissing from a leak).
* Use a fuel pressure gauge: This is the most reliable way to diagnose fuel delivery issues.
* Don't be afraid to consult a manual: A service manual for your 1978 CJ5 can be a valuable resource for troubleshooting procedures and specifications.
Safety Precautions:
* Fuel is flammable: Be extremely cautious when working around gasoline.
* Avoid sparks: Do not work near open flames or electrical equipment.
* Ventilate the area: Work in a well-ventilated area to prevent fuel fumes from accumulating.
If you're unsure about any part of the process, consider seeking help from a mechanic with experience working on classic Jeeps. Good luck!
