Here's a general outline. Specific steps and tool requirements may vary slightly depending on your exact model and trim level. Always consult a repair manual specific to your vehicle year and engine for detailed instructions and diagrams.
1. Safety Precautions:
* Disconnect the negative battery terminal. This is paramount to prevent electrical shorts and sparks.
* Relieve fuel system pressure. This is typically done by disconnecting the fuel pump relay (locate in the under-hood fuse box – consult your owner's manual) and then starting the engine until it stalls. The engine will run for a short time on the remaining fuel in the line before stalling. Alternatively, you can use a fuel pressure gauge to verify pressure is relieved. Do not attempt this step if you are unsure how to safely do it.
* Work in a well-ventilated area. Fuel fumes are flammable and dangerous.
* Wear safety glasses and gloves.
2. Accessing the Fuel Pump:
* Lower the fuel tank. This is usually the most challenging part. You'll likely need to:
* Support the tank with jack stands. Never work under a vehicle supported only by a jack.
* Disconnect the fuel lines. This will involve using fuel line disconnect tools to avoid damaging the lines. Have rags ready to absorb any spilled fuel.
* Disconnect the fuel tank electrical connector.
* Disconnect the fuel tank sending unit (fuel level sensor).
* Unbolt the tank straps holding the tank in place. This might involve removing some components like the exhaust system components that are in the way. Access varies significantly by model, so your repair manual will be helpful here.
* Carefully lower the tank.
3. Replacing the Fuel Pump:
* Locate the fuel pump assembly. It's usually accessed from the top of the tank.
* Remove the retaining ring or cover holding the fuel pump assembly in place. This might involve special tools depending on the design.
* Carefully remove the old fuel pump assembly. Take note of how everything is connected, including electrical connections and any o-rings.
* Install the new fuel pump assembly. Make sure to install any gaskets or seals correctly to prevent leaks. Ensure the electrical connections are secure.
4. Reassembly:
* Raise the fuel tank back into place. Be careful not to damage any fuel lines or components.
* Reconnect the fuel lines, electrical connector, and sending unit. Double-check all connections.
* Reconnect the negative battery terminal.
* Check for leaks: Carefully inspect all connections for leaks before starting the engine.
5. Priming the Fuel System:
* Many modern systems self-prime; however, if the engine doesn't start, you may need to cycle the ignition switch (key on, then off) a few times to allow the pump to prime the system with fuel.
Important Considerations:
* Repair Manual: A Chilton's or Haynes repair manual specific to your 1990 Dodge Dakota 3.9L is highly recommended. It will provide detailed instructions, diagrams, and torque specifications.
* Tools: You will need various tools, including sockets, wrenches, screwdrivers, jack stands, fuel line disconnect tools, and potentially a fuel pump installation tool.
* Fuel Pump Choice: Purchase a high-quality fuel pump that meets the specifications for your vehicle.
* Professional Help: If you are not comfortable performing this repair yourself, it's best to take your vehicle to a qualified mechanic.
This is a general overview. The specifics will vary depending on your truck. Again, always consult a repair manual for your specific vehicle before attempting this repair. Improperly performing this repair can result in damage to your vehicle, injury, or fire.
