1998-1999 Acura RL Fuel Pump: Diagnosing No-Start Issues & Main Relay Problems
Before you replace the fuel pump in your 1998-1999 Acura RL, learn how a faulty main relay can mimic the exact same symptoms and how to tell the difference.
- Always suspect the PGM-FI Main Relay before the fuel pump. A no-start condition, especially when the car is hot, strongly points to a bad relay, which is a cheaper and easier fix.
- When you turn the key to the 'ON' position, listen for the 2-second hum of the fuel pump; if it's silent, the main relay or pump's electrical circuit is the likely problem.
- If replacing the pump, always buy the complete assembly and install a new fuel strainer and tank seal to ensure reliability and prevent premature failure.
- A quality used OEM fuel pump assembly is often more reliable and a better value than a new, inexpensive aftermarket unit for this vehicle.
Is It Your Fuel Pump or the Main Relay?
For many 1990s and 2000s Honda and Acura vehicles, including the 1998-1999 RL, a no-start condition is frequently caused by a faulty PGM-FI Main Relay, not the fuel pump itself. This relay powers both the fuel pump and the engine computer (ECU). Over time, solder joints inside the relay can crack, causing an intermittent or complete loss of power to the fuel pump. This problem is especially common in hot weather. Before spending time and money on a fuel pump replacement, performing a simple check can save you a major headache.
Pro Tip: When you turn the ignition key to the 'ON' (II) position, you should hear two things: a distinct 'click' from under the dashboard (the main relay turning on) and a faint 2-second 'hum' or 'buzz' from the rear seat area (the fuel pump priming). If you don't hear the hum, the main relay is the primary suspect.
Symptoms of a Failing Fuel Pump or Main Relay
Because the main relay controls the fuel pump, their failure symptoms are nearly identical. Pay close attention to these warning signs:
- Engine Cranks but Won't Start: This is the most common and definitive symptom. The engine turns over, but it never fires up because it's not receiving fuel.
- Intermittent No-Start: The car may fail to start, but then start perfectly fine 20 minutes later after it has cooled down. This strongly points to a failing main relay.
- Engine Stalls Unexpectedly: The engine may stall while driving, sometimes at a stoplight, due to a sudden loss of fuel pressure. It might restart immediately or require a cool-down period.
- Hesitation or Sputtering: While accelerating or driving at highway speeds, the engine may sputter or hesitate as the failing pump struggles to supply enough fuel.
- Loss of Power: You may notice a significant drop in power, especially under heavy load like climbing a hill or accelerating hard.
- Loud Whining Noise: A failing fuel pump motor may produce a loud, constant whining or humming sound from the fuel tank area.
Known Issues, Recalls, and TSBs
As of this writing, there are no specific recalls or Technical Service Bulletins (TSBs) issued by the NHTSA for fuel pump failure on the 1998-1999 Acura RL. However, the PGM-FI Main Relay issue is a widely documented problem across many Honda and Acura models of this era. Other recalls for this vehicle concern the airbag inflators and a transmission case bolt, but not the fuel system.
Buying a Used Fuel Pump Assembly
For a vehicle of this age, a high-quality used OEM fuel pump assembly is often a more reliable and cost-effective choice than a cheap, new aftermarket unit. The original Denso-made pumps are built to a high standard. Here’s what to look for when buying a recycled part:
- Buy the Complete Assembly: Always purchase the entire fuel pump module, which includes the pump, fuel level sending unit, housing, and internal wiring. This ensures all components are designed to work together and simplifies installation.
- Inspect the Electrical Connector: Check the main electrical connector on top of the assembly. Look for any signs of melted plastic, charring, or corroded pins. A damaged connector indicates a serious electrical issue and the part should be rejected.
- Check the Plastic Housing: Carefully inspect the white or off-white plastic housing for any cracks, especially around the mounting points and hose connections. Age and fuel exposure can make the plastic brittle.
- Examine the Strainer: If the original strainer is still attached, note its color. A light tan or off-white color is normal. A dark brown or black strainer suggests it came from a vehicle with a very dirty fuel tank, and the pump may have been overworked. Regardless of its condition, you must install a new strainer.
- Verify Compatibility: Ensure the part numbers and, most importantly, the electrical connector design match your original unit before purchasing.
Warning: Always replace the fuel strainer (sometimes called a sock) when installing a new or used fuel pump. Failure to do so can cause the pump to ingest debris, leading to premature failure and voiding any warranty.
Cost Comparison
| Part Type | Estimated Cost |
|---|---|
| New OEM (Dealer) | $1,463 - $1,672 (Part only) |
| New Aftermarket | $50 - $400 |
| Used OEM (Recycled) | $35 - $100 |
| Shop Labor | $100 - $300 |
Replacement Overview (Difficulty: 3/5)
Replacing the fuel pump on a 1998-1999 Acura RL is moderately difficult and requires handling flammable gasoline. If you are not comfortable working with fuel systems, this job is best left to a professional. The fuel pump is located inside the fuel tank.
- Relieve Fuel Pressure: This is a critical safety step. Remove the fuel pump fuse or relay and run the engine until it stalls.
- Disconnect Battery: Disconnect the negative battery terminal.
- Access the Pump: On some related models, an access panel is located in the trunk under the carpet or by removing the rear seat cushion. If no access panel exists, the fuel tank must be lowered to access the pump.
- Clean the Area: Thoroughly clean the top of the fuel pump assembly and the surrounding area to prevent dirt from falling into the tank.
- Disconnect Lines: Carefully disconnect the electrical connector and the fuel lines. Be prepared for some residual fuel spillage.
- Remove the Assembly: Unbolt the retaining nuts that hold the pump assembly to the tank and carefully lift it out.
- Install New Unit: Install the new assembly with a new tank gasket/seal. Installation is the reverse of removal.
Frequently Asked Questions
How do I know for sure if my main relay is bad?
The most common sign is an intermittent no-start that happens when the car's interior is hot. You can try to start the car, and if it just cranks, turn the key off. Wait 15-20 minutes for it to cool down and try again. If it starts normally, the main relay is almost certainly the culprit. A visual inspection of the relay's circuit board may also reveal cracked solder joints.
Do I have to drop the fuel tank to replace the pump?
It depends. Many Honda/Acura vehicles of this era have an access panel under the rear seat or in the trunk, which allows you to replace the pump without removing the tank. However, some service information suggests the tank may need to be lowered. You should inspect your vehicle's trunk and under-seat area for an access cover before beginning the job.
Can I just replace the pump motor instead of the whole assembly?
While it is possible to buy just the internal pump motor, it is not recommended. Replacing only the motor requires disassembling the plastic housing, which can be brittle and break easily. Buying a complete used OEM or new assembly is a much safer and more reliable repair that also replaces the fuel level sender, which can also fail with age.
What is the correct fuel pressure for a 1998-1999 Acura RL?
While specific OEM pressure specs for the RL are not readily available in public sources, typical Honda/Acura fuel systems of this era operate around 40-47 PSI with the engine running. A fuel pressure test is the definitive way to confirm if the pump is weak.
Technical Specifications
OEM Part Numbers: 17040-SP0-A50 17040-SZ3-A31 17040-SZ3-A32 17040-SZ3-A50
Fits 3.5L V6 engine. Fuel pressure for similar Honda/Acura systems is approximately 40-47 PSI.
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Acura RL: