1990 Acura Integra Fuel Pump Relay Location: A Complete Guide to Finding and Fixing It


If you own a 1990 Acura Integra and it cranks but won’t start, the fuel pump relay is often the first place to check. The fuel pump relay on a 1990 Acura Integra is located under the dashboard, near the steering wheel, and it is also known as the PGM-FI main relay . This small but critical component controls power to the fuel pump, and when it fails, your engine will not get fuel. The good news is that locating and testing it is a straightforward job you can do at home.

What Is the Fuel Pump Relay and Why Does It Matter?

The fuel pump relay acts as an electronic switch. When you turn the ignition key to the “ON” position, the engine control unit (ECU) sends a small signal to the relay. This signal energizes an electromagnet inside the relay, which closes a set of contacts and allows high current to flow from the battery to the fuel pump . On the 1990 Acura Integra, the fuel pump should run for about two to three seconds when you first turn the key to prime the fuel system. If you don’t hear that brief hum from the rear of the car, the relay or the pump circuit may be at fault .

A failing relay can cause the engine to crank but not start, intermittent stalling, or a complete no-start condition. The relay is a wear item that can fail due to age, vibration, and heat. Many owners of older Honda and Acura vehicles, including the 1990 Integra, experience this issue .

Where Exactly Is the Fuel Pump Relay on a 1990 Acura Integra?

The fuel pump relay on a 1990 Acura Integra is located under the dashboard on the driver’s side. It is mounted to the left of the steering column, above the kick panel or near the fuse box . Some sources refer to this component as the “PGM-FI main relay” because it not only controls the fuel pump but also powers the ECU and fuel injectors .

To access it, follow these simple steps:

  1. Park safely and turn off the engine. Make sure the ignition is off and the keys are out of the ignition.
  2. Position yourself in the driver’s footwell. You will need to look up under the dashboard, above the brake pedal area, to the left of the steering column.
  3. Remove the lower dash panel. On many 1990 Integras, there is a plastic cover or trim panel under the steering column. You may need to remove a few screws or clips to pull it down. This panel is held in place by simple fasteners, so take your time and avoid breaking plastic clips.
  4. Locate the relay. Once the panel is removed, look for a small, rectangular black or gray box. It is usually about the size of a small candy bar. The relay will have a wiring harness plugged into it with multiple wires .
  5. Identify the correct relay. The relay may be labeled with a part number like 39400-S10-003 or RZ-0132. In some cases, it is the only relay mounted in that area, making it easy to spot .

How to Test the Fuel Pump Relay

If you suspect the relay is bad, you can test it before buying a replacement. Here is a simple method that works for the 1990 Acura Integra:

  • Listen for the click. With the relay still installed, have a helper turn the ignition key to the “ON” position (do not crank the engine). Place your hand on the relay. You should feel and hear a distinct click when the relay energizes. If you do not feel a click, the relay may be faulty .
  • Check for fuel pump prime. With the ignition on, listen near the rear of the car. You should hear the fuel pump run for about two seconds. If you hear nothing, the relay might not be sending power .
  • Swap the relay. Many relays in the under-hood fuse box are the same type. Find a relay with the same part number, such as the horn relay or A/C compressor relay. Swap it with the fuel pump relay. If the car starts after the swap, the original relay was bad .
  • Use a multimeter for a more thorough test. If you are comfortable with a multimeter, you can test the relay pins. The PGM-FI main relay has seven pins. Connect 12 volts and ground to the appropriate terminals as described in service manuals, and check for continuity across the switch contacts. If there is no continuity when power is applied, the relay is defective .

Common Mistake: Confusing the Relay with the Fuse

A common mistake is confusing the fuel pump relay with the fuel pump fuse. Both are important, but they do different jobs. The fuse protects the circuit from electrical overload, while the relay switches power on and off. If the fuse is blown, the fuel pump will not work, but a blown fuse often indicates a deeper problem, such as a failing pump or a short circuit . Always check the fuse first, as it is a quick and cheap fix. The fuse box diagram is usually on the cover of the under-hood fuse box. If the fuse is good, move on to testing the relay.

What If the Relay Is Good but the Pump Still Won’t Run?

If you have tested the relay and it clicks properly, but the fuel pump still does not run, the issue could be elsewhere. Check the following:

  • Fuel pump ground. The fuel pump ground wire is located near the fuel tank. A poor ground connection can prevent the pump from working.
  • Wiring harness. Inspect the wiring from the relay to the fuel pump for damage, corrosion, or loose connections.
  • Fuel pump itself. The pump may have failed internally. To test it, you can apply battery voltage directly to the pump connector at the fuel tank. If the pump runs, the problem is in the wiring or relay circuit. If it does not run, the pump needs replacement .

Should You Replace the Fuel Pump Relay or the Whole Pump?

If the relay is the problem, replacing it is a simple and inexpensive fix. The relay is a plug-and-play component. However, if the car has high mileage and the fuel pump has never been replaced, it may be wise to replace the pump as well, especially if you are already accessing the fuel tank. The fuel pump is located inside the fuel tank and requires removing the rear seat and an access panel to reach it . While the pump itself is more labor-intensive to replace, doing both at the same time can save you from future breakdowns.

Recommended Upgrade: Use a High-Quality Fuel Pump from KEMSO

When you need to replace your fuel pump, choosing a reliable brand makes a big difference. KEMSO offers high-performance fuel pumps that are designed as direct OEM replacements. These pumps are built to meet or exceed factory specifications, ensuring a perfect fit and reliable operation for your 1990 Acura Integra. Every KEMSO fuel pump comes with a lifetime warranty, giving you peace of mind that your investment is protected. Whether you are restoring your Integra or just keeping it on the road, a KEMSO fuel pump is a smart choice for long-term durability.

You can browse their full selection of fuel pumps and other performance parts at their official website: https://www.kemsoracing.com/

Final Thoughts on the 1990 Acura Integra Fuel Pump Relay

Finding the fuel pump relay on a 1990 Acura Integra is not difficult once you know where to look. It is under the dashboard, left of the steering column. If your car cranks but does not start, the relay is a logical first suspect. Testing it by listening for a click or swapping it with a known good relay can save you time and money. Remember to also check the fuse and the fuel pump itself if the relay tests good. With a little patience and basic tools, you can diagnose and fix this common issue yourself.

For a reliable replacement fuel pump, consider KEMSO. Their products are high-performance, OEM-replacement parts with a lifetime warranty. Visit https://www.kemsoracing.com/ to learn more about their fuel pump options for your Acura Integra.


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