A Guide to the Electric Fuel Pump for the 1987 GMC V2500
Here is what you need to know before buying and replacing the electric fuel pump on your 1987 GMC V2500 truck.
- Before replacing the pump, test the fuel pump relay and oil pressure switch, as they are common failure points.
- For trucks with dual tanks, a faulty selector switch or valve can mimic a bad pump.
- Investing in a quality brand like Delphi is recommended due to the high labor cost of replacement.
- Ensure you order the correct pump assembly for your specific tank size (e.g., 31-gallon) and configuration.
Is Your Fuel Pump Failing?
A bad fuel pump in your 1987 V2500 will usually give you clear signs of trouble. Because this part is essential for delivering fuel, a complete failure will prevent the engine from running at all. You might notice the truck cranks but won't start, or it might stall suddenly while driving and refuse to restart. Other common symptoms include a noticeable loss of power, especially when accelerating or hauling a load, and engine sputtering at highway speeds. A distinct whining or humming sound from the fuel tank area is another classic sign of a pump that is working too hard and about to fail. One of the first checks is to listen for the pump to hum for two seconds when you turn the key to the 'on' position; if it's silent, the pump is likely not getting power or has failed.
Pro Tip: Check These First!
Before you blame the fuel pump, check a few other related parts. The fuel pump gets its power through a relay, which is often located on the firewall. These trucks also use an oil pressure switch as a safety backup to power the pump, which can also be a point of failure. If you have dual fuel tanks, a faulty tank selector switch on the dash or the selector valve on the frame can mimic the symptoms of a bad pump. Testing these cheaper, easier-to-replace components first can save you a lot of time and money.
Choosing the Right Aftermarket Fuel Pump
Since original OEM fuel pumps for a 1987 vehicle are generally not available, you will be choosing from aftermarket brands. The labor involved in replacing the pump is significant, so choosing a quality part to avoid doing the job twice is highly recommended by mechanics and owners.
- Premium Brands (Delphi): Delphi is a well-regarded brand that was often an original equipment manufacturer for GM. Their pumps are known for reliability and proper fitment. Choosing a Delphi pump is often considered a safe bet for longevity, which is important given the difficulty of the replacement job.
- Standard Brands (AutoBest): Brands like AutoBest fall into the standard replacement category. They offer a balance of affordability and function, meeting original specifications. While they can be a good value, they may not have the same reputation for long-term durability as premium OEM-supplier brands.
- Performance Brands (Edelbrock): Edelbrock is known for high-performance parts. While they make excellent products, their fuel pumps are often universal or designed for higher-than-stock horsepower applications. A performance pump might require modifications to your fuel lines or wiring and may not be a direct-fit replacement. Stick to OEM-style replacement pumps unless you have a modified engine.
Known Issue: Loose In-Tank Reservoir
A Technical Service Bulletin (TSB 88-T-80) was issued for similar 1987-88 GM trucks and SUVs for a condition where the plastic fuel pump reservoir on the bottom of the tank can come loose. This can dislodge the fuel pump from the sending unit, causing it to stop working. When the tank is down for the pump replacement, it is a good idea to inspect this reservoir and ensure it is securely attached to the bottom of the tank.
Frequently Asked Questions (FAQ)
Can I replace the fuel pump myself?
This is a challenging job for a DIY mechanic. It requires either lifting the truck bed or safely draining and dropping the fuel tank. Both methods require significant space, tools, and safety precautions when dealing with gasoline. If you are not experienced, professional installation is recommended.
Should I buy just the pump or the whole assembly?
It is highly recommended to buy the complete fuel pump module or assembly, which includes the pump, sending unit, strainer, and float. This ensures all components are new and compatible. Trying to replace just the pump motor on the old sending unit can be difficult and may lead to incorrect readings on your fuel gauge or other issues.
My truck has dual tanks. Does that change things?
Yes. Each tank has its own fuel pump. If only one tank is giving you problems, it's likely the pump in that specific tank or an issue with the selector valve or switch. When ordering, you must specify which tank (left or right) the pump is for.
Why is it a bad idea to buy the cheapest pump available?
The cost of the fuel pump part is often much less than the cost of the labor to install it. Cheaper pumps have a higher failure rate. Having to pay for the same labor-intensive job again in a year or two will cost you much more in the long run than buying a quality pump from the start.
Technical Specifications
System Type: Throttle Body Injection (TBI) Pump Location: In-Tank Required Pressure: 9-13 PSI Average Flow Rating: ~24 GPH
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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.
- GMC V2500: