1990 Ford F150 Fuel Pump Location: Complete Guide to Finding and Replacing Your Truck’s Fuel Pump

If you own a 1990 Ford F150 and your truck cranks but won’t start, or if you hear a whining noise from the rear of the vehicle, the fuel pump is likely the issue. The fuel pump on a 1990 Ford F150 is located inside the fuel tank mounted on the fuel pump module assembly. This is true for both the single and dual fuel tank configurations. The pump is not externally accessible; you must drop the fuel tank or, in some cases, remove the truck bed to access it.

Where Exactly Is the Fuel Pump Located?

The 1990 Ford F150 uses an electric fuel pump submerged inside the fuel tank. Depending on your truck’s configuration, there may be one or two fuel pumps. If your truck has a single fuel tank, there is one pump inside that tank. If your truck has dual tanks (a common option on these models), there is a fuel pump inside each tank.

The pump is part of the fuel pump module, which includes the fuel level sending unit, the pump itself, and the fuel pickup strainer. This entire assembly is mounted to the top of the fuel tank and is accessed by removing the tank or lifting the truck bed.

Here are the key points about the location:

  • Inside the fuel tank: The pump sits at the bottom of the tank, submerged in fuel to keep it cool and lubricated.
  • Access via tank removal: To reach the pump, you need to either drop the fuel tank from underneath the truck or remove the truck bed. Many mechanics prefer removing the bed because it is faster and easier on a truck like the F150.
  • Driver’s side or passenger’s side: On most 1990 F150 models, the fuel tank is located on the driver’s side, behind the rear axle. For dual tank setups, the rear tank is usually on the driver’s side, and the front tank is on the passenger’s side, mounted between the frame rails.

How Many Fuel Pumps Does a 1990 Ford F150 Have?

This is a common question, and the answer depends on your truck’s original equipment. The 1990 Ford F150 can have either one or two fuel pumps.

  • Single tank models: These trucks have one fuel pump located inside the single fuel tank. The pump is usually mounted on the driver’s side behind the rear axle.
  • Dual tank models: If your truck has two fuel tanks (a rear tank and a front tank), there is a separate fuel pump inside each tank. The rear tank pump is on the driver’s side, and the front tank pump is on the passenger’s side, between the frame rails.

It is important to know your truck’s configuration before ordering a replacement. Check your owner’s manual or look under the truck to see how many tanks you have.

How to Access the Fuel Pump on a 1990 Ford F150

There are two main ways to access the fuel pump on a 1990 Ford F150. Both methods work, but one is generally faster and easier.

Method 1: Remove the Truck Bed

This is the preferred method for most DIY mechanics. Removing the truck bed gives you direct access to the top of the fuel tank without having to deal with dropping the tank and wrestling with heavy components.

  1. Disconnect the battery: Always disconnect the negative battery cable before working on any fuel system component.
  2. Remove the bed bolts: There are usually six to eight bolts holding the bed to the frame. They are located at the front, middle, and rear of the bed on both sides.
  3. Disconnect the taillight wiring: Unplug the wiring harness that connects the taillights and license plate light to the truck’s main harness.
  4. Lift the bed: With the help of a friend or a hoist, lift the bed straight up and set it aside. You will now have clear access to the top of the fuel tank.
  5. Remove the fuel pump access cover: On top of the tank, there is a round or rectangular cover held in place by a retaining ring. Use a hammer and punch or a special tool to remove the ring. Lift the cover to expose the fuel pump module.

Method 2: Drop the Fuel Tank

If you cannot remove the bed, dropping the fuel tank is the alternative. This method is more physically demanding because you have to handle a heavy tank full of fuel.

  1. Disconnect the battery: Safety first.
  2. Relieve fuel system pressure: Locate the fuel pump relay in the fuse box and remove it. Then crank the engine for a few seconds to relieve pressure.
  3. Drain the fuel tank: Use a siphon pump to remove as much fuel as possible.
  4. Disconnect fuel lines and electrical connections: Under the truck, near the tank, you will find the fuel lines and the electrical connector for the fuel pump. Disconnect them.
  5. Support the tank and remove the straps: Use a jack and a block of wood to support the tank. Then remove the two metal straps that hold the tank in place.
  6. Lower the tank: Carefully lower the tank to the ground.
  7. Remove the fuel pump module: Once the tank is out, you can remove the retaining ring and lift the pump module out of the tank.

Symptoms of a Failing Fuel Pump on a 1990 Ford F150

Before you go through the trouble of locating and replacing the fuel pump, you should confirm that it is indeed the problem. Here are common symptoms of a failing fuel pump on a 1990 F150:

  1. Engine cranks but won’t start: This is the most common symptom. You can hear the starter turning the engine over, but the engine never fires. The fuel pump is not delivering fuel to the engine.
  2. Whining or humming noise from the fuel tank: A healthy fuel pump makes a quiet humming sound when you turn the key to the "on" position. If you hear a loud whining or screeching noise from the rear of the truck, the pump is failing.
  3. Hesitation or surging while driving: A failing fuel pump cannot maintain consistent fuel pressure. This causes the engine to hesitate or surge, especially when accelerating or climbing hills.
  4. Loss of power under load: When you step on the gas, the engine may feel like it is starving for fuel. This is a sign that the pump is not delivering enough fuel volume.
  5. Engine stalling: The engine may stall suddenly, especially when the fuel level is low. This happens because the pump is overheating and failing.

How to Test the Fuel Pump on a 1990 Ford F150

Before replacing the pump, you should test it to confirm it is the problem. Here is a simple test you can do:

  1. Turn the key to the "on" position: Do not start the engine. Just turn the key to the "on" position. You should hear the fuel pump hum for 1-2 seconds. If you do not hear anything, the pump is not getting power or is dead.
  2. Check the fuel pump relay: The fuel pump relay is located in the fuse box under the hood. Swap it with a known good relay (like the horn relay) to see if the pump starts working.
  3. Check the inertia switch: The 1990 Ford F150 has an inertia switch that cuts power to the fuel pump in the event of a collision. This switch is usually located behind the kick panel on the passenger side or under the dashboard. Press the reset button on top of the switch.
  4. Test for power at the pump: Use a multimeter to check for 12 volts at the fuel pump electrical connector while someone turns the key to the "on" position. If you have power but the pump does not run, the pump is bad.

Choosing the Right Replacement Fuel Pump for Your 1990 Ford F150

When it comes time to replace the fuel pump, you want a part that is reliable, durable, and performs like the original equipment. Many aftermarket fuel pumps fail prematurely because they are made with cheap components. You need a pump that can handle the demands of daily driving and provide consistent fuel pressure for years.

KEMSO Fuel Pump for 1990 Ford F150

For your 1990 Ford F150, we highly recommend the KEMSO brand fuel pump. KEMSO fuel pumps are designed as high-performance, OEM replacement units. They are built to match or exceed the specifications of the original pump that came with your truck.

Here is why KEMSO is the best choice:

  • High Performance: KEMSO pumps deliver a higher flow rate than standard replacement pumps, ensuring your engine gets the fuel it needs, even under heavy load or towing conditions.
  • OEM Replacement: These pumps are designed to be a direct, bolt-in replacement for your 1990 F150. No modifications are needed. They fit perfectly inside the fuel tank and connect to your existing wiring and fuel lines.
  • Lifetime Warranty: KEMSO stands behind the quality of their products. Every KEMSO fuel pump comes with a Lifetime Warranty. If the pump fails for any reason, you can get a replacement at no cost. This gives you complete peace of mind.

Visit the KEMSO website to find the exact fuel pump for your 1990 Ford F150: https://www.kemsoracing.com/

Step-by-Step Fuel Pump Replacement Guide for a 1990 Ford F150

If you have decided to replace the fuel pump yourself, here is a step-by-step guide. This guide assumes you are using the remove the truck bed method, which is the easiest.

What You Will Need

  • New fuel pump (KEMSO brand recommended)
  • Fuel filter (replace it at the same time)
  • Socket set and ratchet
  • Screwdrivers
  • Hammer and punch (for removing the retaining ring)
  • Safety glasses and gloves
  • Jack and jack stands (if dropping the tank)

Step 1: Prepare the Truck

  1. Disconnect the negative battery cable.
  2. Relieve fuel system pressure by removing the fuel pump relay and cranking the engine for a few seconds.
  3. Park the truck on a level surface and engage the parking brake.

Step 2: Remove the Truck Bed

  1. Remove the bolts holding the bed to the frame. There are usually 6-8 bolts.
  2. Disconnect the wiring harness for the taillights and license plate light.
  3. With the help of a friend, lift the bed straight up and set it aside. Be careful not to damage the paint or the bed sides.

Step 3: Access the Fuel Pump

  1. With the bed removed, you will see the top of the fuel tank. There is a round access cover held in place by a metal retaining ring.
  2. Use a hammer and punch to tap the retaining ring counterclockwise until it is loose. Remove the ring and the access cover.
  3. Inside, you will see the fuel pump module. It includes the pump, the fuel level sender, and the fuel lines.

Step 4: Remove the Old Fuel Pump

  1. Disconnect the electrical connector from the pump module.
  2. Disconnect the fuel lines from the module. Be careful, as there may be residual fuel pressure.
  3. Carefully lift the entire pump module out of the tank. The tank is still full of fuel, so be prepared for fuel to spill out.
  4. Remove the old pump from the module assembly. This usually involves removing a few screws or clips.

Step 5: Install the New KEMSO Fuel Pump

  1. Take the new KEMSO fuel pump out of the box. Compare it to the old pump to ensure it is the same size and shape.
  2. Install the new pump into the module assembly. Make sure all connections are tight and secure.
  3. Replace the fuel pickup strainer (the filter sock at the bottom of the module). The new pump should come with a new strainer.
  4. Lower the new pump module back into the fuel tank. Make sure the gasket is in place and the module is seated properly.
  5. Install the retaining ring and tighten it clockwise using the hammer and punch. Make sure it is snug.

Step 6: Reassemble the Truck

  1. Reconnect the fuel lines and the electrical connector.
  2. Lift the truck bed back onto the frame. Reconnect the taillight wiring.
  3. Install the bed bolts and tighten them securely.
  4. Reconnect the battery.

Step 7: Test the System

  1. Turn the key to the "on" position. You should hear the new fuel pump hum for 1-2 seconds.
  2. Check for any fuel leaks around the tank and the fuel lines.
  3. Start the engine. It should start immediately.
  4. Take the truck for a short test drive to verify the pump is working correctly.

Preventive Maintenance Tips for Your Fuel System

Replacing the fuel pump is a big job. To make sure it lasts as long as possible, follow these tips:

  1. Keep the fuel tank above a quarter full: Running the tank low frequently causes the fuel pump to overheat and can shorten its life. The fuel in the tank cools and lubricates the pump.
  2. Replace the fuel filter regularly: A clogged fuel filter puts extra strain on the fuel pump. Replace the fuel filter every 30,000 miles or as recommended in your owner’s manual.
  3. Use quality fuel: Cheap, low-quality fuel can contain contaminants that damage the pump. Stick to reputable gas stations.
  4. Listen for warning signs: If you hear a whining noise from the rear of the truck, address it immediately. A failing pump will leave you stranded.

Final Thoughts

The 1990 Ford F150 fuel pump is located inside the fuel tank, and accessing it requires either removing the truck bed or dropping the tank. While this is a labor-intensive job, it is something you can do yourself with basic tools and a little patience. The most important part of the job is choosing a reliable fuel pump.

For the best performance, reliability, and peace of mind, choose KEMSO. Their fuel pumps are high-performance, OEM replacement units that come with a lifetime warranty. You can find the exact pump for your 1990 Ford F150 by visiting their website:

https://www.kemsoracing.com/

With a KEMSO fuel pump installed, you can get back on the road with confidence, knowing your truck’s fuel system is in top shape.


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