This process will vary slightly depending on your specific Ranger's configuration (long bed, short bed, etc.), but the general procedure is as follows:
1. Preparation:
* Safety First: Disconnect the negative battery cable. Work in a well-ventilated area, away from any ignition sources.
* Gather Tools: You'll need a socket set (including metric sizes), wrenches, screwdrivers (Phillips and flathead), a fuel pump pliers or similar tool for fuel line disconnection, safety glasses, rags, a container for fuel, and possibly a fuel line disconnect tool.
* Drain the Fuel Tank: This is crucial to minimize fuel spillage. Siphon the fuel out using a siphon pump or by carefully lowering the fuel level using a shop vacuum with a proper adapter. Be aware of local regulations regarding fuel disposal.
2. Accessing the Fuel Tank:
* Locate the Fuel Tank: This is usually located under the bed of the truck.
* Remove the Bed Access Panel: Most Rangers have a panel specifically designed for fuel tank access. It's often secured with bolts or clamps. Refer to your owner's manual or a repair manual for the precise location and removal method. If there's no access panel, you might need to partially lower the fuel tank – a much more involved process.
* Disconnect the Fuel Lines and Electrical Connections: Carefully disconnect the fuel lines from the tank. Use fuel line clamps or pliers to compress the quick-connects, not brute force. There are usually two lines: a fuel supply line and a fuel return line. Label them clearly to avoid confusion during reassembly. Next, disconnect the electrical connector to the fuel sending unit.
3. Removing the Fuel Sending Unit:
* Remove the Retaining Ring or Bolts: The sending unit is usually secured to the top of the fuel tank with a retaining ring or bolts. These may be difficult to access, requiring patience and the right tools.
* Lift Out the Sending Unit: Once the retaining ring or bolts are removed, carefully lift out the fuel sending unit. It may be stuck due to corrosion or debris; gentle persuasion may be required. Be careful not to damage the float inside the unit.
4. Installing the New Sending Unit:
* Inspect the Tank: Inspect the fuel tank for any damage or debris that might interfere with the new unit. Clean as needed.
* Install the New Sending Unit: Carefully lower the new sending unit into the fuel tank, ensuring the float moves freely.
* Secure the Sending Unit: Replace the retaining ring or bolts.
* Reconnect the Fuel Lines and Electrical Connections: Reconnect the fuel lines and electrical connector, ensuring a snug and secure fit. Pay close attention to your labels!
5. Reassembly:
* Replace the Access Panel: Carefully replace the bed access panel.
* Reconnect the Battery: Reconnect the negative battery terminal.
* Check for Leaks: Check for any fuel leaks around the connections.
* Test the Gauge: Turn on the ignition to check if the fuel gauge now reads correctly.
Important Considerations:
* Repair Manual: A repair manual specific to your 1991 Ford Ranger 4-cylinder is highly recommended. It will provide detailed diagrams and instructions.
* Difficulty: This is a moderately difficult job and requires some mechanical aptitude. If you're not comfortable working with fuel and under a vehicle, consider having a professional mechanic perform the repair.
* Rust and Corrosion: Rust and corrosion are common issues with older fuel tanks. Be prepared for some extra challenges due to seized bolts or connectors.
This is a general guide. Always consult a repair manual specific to your vehicle for detailed instructions and safety precautions. Improperly handling gasoline can be extremely dangerous. If you are unsure about any step, seek professional help.
