1991 Honda Civic Fuel Pump: Complete Replacement Guide and Cost Breakdown

If your 1991 Honda Civic cranks but won't start, or if it sputters and loses power during acceleration, the fuel pump is likely failing. The 1991 Honda Civic fuel pump is located inside the fuel tank and can be accessed through a panel under the rear seat on most models. Replacing it yourself costs between $100 and $200 in parts, while professional replacement runs $389 to $735. This guide walks you through everything you need to know about diagnosing, replacing, and choosing the right fuel pump for your 1991 Civic.

Why Your 1991 Honda Civic Fuel Pump Matters

The fuel pump in your 1991 Honda Civic is responsible for delivering gasoline from the fuel tank to the engine at the correct pressure and volume. Without a properly working pump, the engine simply will not run. The 1991 model year covers the fourth generation Civic (chassis code ED, EE, EF), which includes the hatchback, sedan, and CRX variants. These cars came with either a 1.5L or 1.6L four-cylinder engine, and all use an electric fuel pump mounted inside the fuel tank.

Signs Your 1991 Honda Civic Fuel Pump Is Failing

Before you spend money on a new pump, confirm that the fuel pump is actually the problem. These are the most common symptoms of a failing fuel pump on a 1991 Civic:

1. Engine cranks but will not start. This is the most obvious sign. If you turn the key and the engine turns over but never fires up, and you do not hear a two-second humming sound from the rear of the car when you turn the key to the ON position, the pump is likely dead.

2. Loss of power under load. A weak pump may still deliver enough fuel at idle but fail when you need more fuel during acceleration or climbing hills. The car may hesitate, surge, or feel like it is running out of gas even with a full tank.

3. Engine sputtering at high speeds. If the car runs fine around town but starts to sputter or cut out on the highway, the pump may be struggling to maintain fuel pressure at higher RPMs.

4. Whining noise from the fuel tank. A healthy fuel pump makes a quiet hum. If you hear a loud whining or buzzing sound coming from the rear of the car, especially when the tank is low, the pump bearings are wearing out and replacement is imminent.

5. Check engine light comes on. On OBD-I equipped 1991 Civics, a failing fuel pump can trigger a trouble code. You can read the code by looking at the flashing light on the ECU under the passenger seat.

How to Diagnose the Fuel Pump on a 1991 Honda Civic

Do not just throw a new pump at the problem. Run these simple tests first:

Step 1: Listen for the pump. Turn the ignition key to the ON position (do not start the engine). Stand near the rear of the car and listen for a two-second hum. If you hear nothing, the pump is not getting power or has failed.

Step 2: Check the fuel pump relay and fuse. The fuel pump relay on a 1991 Civic is located behind the glove box. The fuel pump fuse is in the under-dash fuse box. A blown fuse or a bad relay will mimic a dead pump perfectly. Swap the relay with an identical one (like the horn relay) to test it.

Step 3: Check voltage at the pump. Remove the access panel under the rear seat and locate the electrical connector on top of the fuel tank. With the key in the ON position, you should see 12 volts at the pump connector. If voltage is present but the pump does not run, the pump itself is bad.

1991 Honda Civic Fuel Pump Location

The fuel pump on a 1991 Honda Civic is mounted inside the fuel tank. The good news is that you do not need to drop the fuel tank to access it. The pump is accessible through an access panel located under the rear seat cushion.

Where to find it: Remove the rear seat bottom cushion. On the 1991 Civic, the cushion is held in place by a single 10mm bolt near the center of the seat between the bottom and rear sections. Once the seat is removed, you will see a rectangular metal or plastic cover plate held by four Phillips-head screws. Remove these screws and you will see the top of the fuel pump assembly.

Tools You Will Need for the Job

Replacing the fuel pump on a 1991 Honda Civic requires a few specific tools. Gather these before you start:

• 10mm socket and ratchet (for the seat bolt and the pump cover nuts)
• 17mm wrench or socket (for the banjo bolt on the fuel line)
• Phillips-head screwdriver (for the access panel screws)
• Small flat-head screwdriver (for releasing electrical connectors)
• Fuel line disconnect tool (for the quick-connect fittings)
• Brass drift and hammer (for the locking ring, if equipped)
• Shop rags and a fire extinguisher (safety first)
• New O-ring and gasket for the pump assembly

Step-by-Step Guide to Replacing the 1991 Honda Civic Fuel Pump

Step 1: Relieve fuel system pressure. Open the fuel filler cap to release any pressure in the tank. Then, locate the PGM-FI relay behind the glove box (it is the relay with yellow/black, yellow/green, yellow/green, and green/yellow wires). Remove it, start the engine, and let it stall. This drains the fuel pressure from the lines.

Step 2: Disconnect the battery. Use a wrench to loosen the clamp on the negative battery terminal and remove it. Secure the cable away from the terminal to prevent accidental sparks.

Step 3: Remove the rear seat. Find the 10mm bolt near the center of the seat between the bottom cushion and the backrest. Remove it, then pull the front edge of the bottom cushion up to release it.

Step 4: Remove the access panel. Use a Phillips-head screwdriver to remove the four screws holding the cover plate in place. Lift the cover off to expose the top of the fuel pump assembly.

Step 5: Vacuum around the opening. Use a shop vacuum to remove any dirt and debris from around the pump opening. Even a small amount of contamination entering the fuel tank can cause the new pump to fail prematurely.

Step 6: Disconnect the electrical connector. Pull the rubber boot up on the connector and press the release tab to disconnect it.

Step 7: Disconnect the fuel lines. On the 1991 Civic, the fuel supply line uses a banjo bolt with crush washers. Use a 17mm wrench to remove the banjo bolt. Have a rag ready because fuel will spill out. Also disconnect the smaller return line by sliding the clamp back and pulling the hose off.

Step 8: Remove the pump assembly. Depending on your specific 1991 Civic model, the pump assembly is held either by a large locking ring or by six 10mm nuts. If it is a locking ring, use a hammer and brass drift to rotate it counterclockwise. If it is nuts, remove them with a 10mm socket.

Step 9: Lift the pump out. Carefully lift the entire pump assembly straight up out of the tank. Tilt it slightly to avoid damaging the fuel level float arm. Let any excess fuel drain back into the tank.

Step 10: Compare the old and new assemblies. Place the old pump next to the new one. Check that the electrical connections, fuel line ports, and the overall shape are identical. The OE part numbers should match. For the 1991 Civic, common OEM part numbers include 17708-SH5-A31 and 17708-SH3-A36.

Step 11: Transfer components if needed. If you are replacing just the pump inside the assembly, work on a clean bench. Remove the old pump from the assembly, transfer the rubber boot, filter, and any insulators or grommets to the new pump. Install the new pump in the reverse order.

Step 12: Install the new pump assembly. Place the new O-ring seal into the mounting hole on the fuel tank. Apply a small amount of fuel to the O-ring to help it seat. Insert the new pump assembly into the tank, aligning the index mark on the top of the assembly between the two marks on the edge of the hole.

Step 13: Secure the pump assembly. Tighten the locking ring or the six nuts. If using nuts, tighten them in a criss-cross pattern to 10 N·m. If using a locking ring, tap it clockwise until it is snug.

Step 14: Reconnect everything. Reconnect the fuel lines with new crush washers on the banjo bolt. Reconnect the return line and slide the clamp back into place. Reconnect the electrical connector and pull the rubber boot back down.

Step 15: Reinstall the access panel and seat. Place the cover plate back on and tighten the four screws. Reinstall the rear seat cushion and tighten the 10mm bolt.

Step 16: Reconnect the battery. Reconnect the negative battery cable. Turn the ignition key to the ON position without starting the engine. You should hear the new fuel pump prime for about two seconds.

Step 17: Check for leaks. Start the engine and let it idle. Inspect all fuel line connections and the pump seal area for any signs of leakage. If you see any fuel, turn off the engine immediately and fix the leak.

Step 18: Take a test drive. Drive the car for a few miles. Accelerate smoothly, climb a hill, and check that the engine runs without hesitation or loss of power.

1991 Honda Civic Fuel Pump Replacement Cost

The cost to replace the fuel pump on a 1991 Honda Civic varies based on whether you do it yourself or hire a professional. Here is what you can expect:

DIY cost: A new fuel pump assembly for the 1991 Civic costs between $76 and $198 for an OEM or high-quality aftermarket unit. You will also need a new O-ring and gasket, adding about $10 to $20. Total DIY cost: approximately $86 to $218.

Professional replacement cost: Based on real repair data, the total cost for a 1991-1995 Civic fuel pump replacement ranges from $389 to $735. This includes both parts and labor. If you go to a dealership, expect to pay on the higher end of that range. An independent shop will charge less. A mobile mechanic may offer the lowest price, with some estimates as low as $223 for parts and labor combined.

Factors that affect the price:

• Parts choice: OEM parts are more expensive but carry a Honda warranty. Aftermarket parts from reputable brands cost less and often perform just as well.
• Shop type: Dealerships charge the highest rates. Independent shops charge less. Mobile mechanics offer the lowest prices.
• Access difficulty: On the 1991 Civic, the pump is accessible through the rear seat, which keeps labor costs lower. Some older models may require dropping the tank, which adds time and cost.

Choosing the Right Fuel Pump for Your 1991 Honda Civic

When buying a replacement fuel pump for your 1991 Civic, you have several options. Here is what to look for:

1. OEM vs. aftermarket. OEM parts are made by Honda's suppliers and carry the Honda warranty. Aftermarket parts are less expensive but may have shorter warranties. Many aftermarket pumps perform just as well as OEM units when sourced from reputable brands.

2. OE part numbers. The correct OEM part numbers for the 1991 Civic fuel pump assembly include 17708-SH5-A31 (replaced by 17040-SH5-A30) and 17708-SH3-A36 / 17708-SH3-A31. Verify your old part number before ordering.

3. Performance upgrades. If you have modified your Civic's engine for more power, consider a high-performance pump like the Walbro GSS278, which flows 190 liters per hour and supports engines with over 500 horsepower. This is a direct-fit replacement for the 1988-1991 Civic.

4. Complete assembly vs. pump only. It is easier to replace the entire fuel pump assembly (which includes the pump, fuel gauge sending unit, and filter). If you only replace the pump itself, you must transfer components from the old assembly.

Why KEMSO Fuel Pumps Are the Right Choice for Your 1991 Honda Civic

When it comes to replacing the fuel pump on your 1991 Honda Civic, you want a part that delivers reliable performance and long-term durability. KEMSO fuel pumps are built to meet these demands.

KEMSO offers high-performance fuel pumps that are designed as direct OEM replacements. This means they fit perfectly into your 1991 Civic's fuel tank without any modifications. The installation process is straightforward and follows the same steps outlined in this guide.

What sets KEMSO apart:

• High performance: KEMSO fuel pumps are engineered to deliver consistent fuel pressure and flow, ensuring your engine runs smoothly under all driving conditions.
• OEM replacement quality: Every KEMSO pump is built to match or exceed the specifications of the original factory pump. You get the same fit, form, and function as the Honda part.
• Lifetime warranty: KEMSO stands behind every fuel pump with a lifetime warranty. If your pump ever fails, KEMSO will replace it. This gives you peace of mind that your investment is protected.

Visit KEMSO Racing today to find the perfect fuel pump for your 1991 Honda Civic. Their selection covers a wide range of vehicles, and the lifetime warranty means you will never have to pay for a replacement pump again.

Safety Precautions for Fuel Pump Replacement

Working with the fuel system is dangerous. Gasoline is highly flammable. Follow these safety rules to protect yourself and your car:

1. Work in a well-ventilated area. Fuel vapors are heavier than air and can accumulate in low spots. Open the garage door and work outside if possible.

2. Disconnect the battery. This prevents accidental sparks from electrical shorts. Always disconnect the negative terminal first.

3. No open flames or sparks. Do not smoke, use a phone, or operate any electrical tools near the work area. Use a brass drift to avoid sparks when removing the locking ring.

4. Have a fire extinguisher nearby. Keep a Class B fire extinguisher (rated for flammable liquids) within reach.

5. Wear safety glasses and gloves. Fuel can irritate your skin and eyes. Protect yourself from splashes.

6. Do not wear loose clothing. Loose clothing can get caught in moving parts or catch fire. Wear fitted work clothes.

7. Use a drip pan. Place a drain pan under the fuel tank to catch any spilled fuel. Dispose of the fuel properly.

Post-Replacement Checks

After you have replaced the fuel pump, there are a few things you should monitor to ensure the repair was successful:

1. Listen for unusual noises. A new pump should make a quiet, steady hum. If you hear a whining or buzzing noise, there may be an installation issue or the pump may be defective.

2. Check for fuel leaks. After the first few drives, inspect the area around the pump access panel and the fuel lines for any signs of leakage. A small leak can quickly become a fire hazard.

3. Monitor engine performance. The engine should start easily, idle smoothly, and accelerate without hesitation. If you experience any of the old symptoms, the problem may not have been the pump.

4. Keep the tank at least a quarter full. The fuel in the tank cools and lubricates the fuel pump. Running the tank low repeatedly can shorten the pump's lifespan.

Frequently Asked Questions

Q: Does the 1991 Honda Civic fuel pump have an access panel?
A: Yes. On most 1991 Civic models, the fuel pump is accessible through a panel under the rear seat. You do not need to drop the fuel tank.

Q: How long does it take to replace the fuel pump on a 1991 Civic?
A: For an experienced DIYer, the job takes about 1 to 2 hours. If you have never done it before, plan for 2 to 3 hours.

Q: Can I drive with a failing fuel pump?
A: It is not recommended. A failing pump can leave you stranded, and a sudden loss of fuel pressure while driving can be dangerous. Replace it as soon as you notice symptoms.

Q: Should I replace the fuel filter at the same time?
A: Yes. It is good practice to replace the fuel filter when you replace the pump. A clogged filter can put extra strain on the new pump and shorten its life.

Q: What is the fuel pressure specification for a 1991 Civic?
A: The 1991 Civic's fuel system operates at approximately 30 to 38 psi, depending on the engine and whether it is a carbureted or fuel-injected model. Most 1991 Civics are fuel-injected.

Final Thoughts

Replacing the fuel pump on your 1991 Honda Civic is a manageable DIY project that can save you hundreds of dollars in labor costs. The pump is easy to access through the rear seat, and the procedure is straightforward. By following the steps in this guide, you can get your Civic back on the road with a reliable fuel delivery system.

If you are not comfortable working with fuel systems, or if you do not have the right tools, it is always safer to have a professional mechanic do the job. The cost of a mistake—a fire, a fuel leak, or a damaged component—far exceeds the labor savings.

For those who want a high-quality replacement that comes with a lifetime warranty, consider KEMSO fuel pumps. They are designed as direct OEM replacements, offer high performance, and are backed by a lifetime warranty. Visit KEMSO Racing at https://www.kemsoracing.com/ to find the right fuel pump for your 1991 Honda Civic. With KEMSO, you get a reliable part that will keep your Civic running smoothly for years to come.