1982 Datsun 720 Fuel Pump: The Complete Guide to Replacement, Performance, and Reliability

If you own a 1982 Datsun 720 pickup and need a fuel pump replacement, the most important thing to know is that your truck can use either a mechanical fuel pump mounted on the engine or an electric fuel pump, depending on the engine configuration and previous modifications. The 1982 model year falls within the 720 series production run from 1979 to 1985, and these trucks came with several engine options including the 1.8L L18, 2.0L L20B, and 2.2L Z22 engines . Choosing the correct fuel pump is essential for reliable engine performance, proper fuel pressure, and long-term durability.

Understanding Your 1982 Datsun 720 Fuel Pump

The 1982 Datsun 720 pickup originally came with a mechanical fuel pump on most carbureted engine models . These pumps are typically located on the side of the engine block and are driven by an eccentric cam lobe on the camshaft. The mechanical pump works by using a diaphragm that creates suction to pull fuel from the tank and push it to the carburetor.

Common symptoms of a failing fuel pump on your 1982 Datsun 720 include:

  • Engine cranks but won't start – If the pump is not delivering fuel, the engine will not fire
  • Poor acceleration or hesitation – A weak pump cannot supply enough fuel under load
  • Engine stalls or runs rough – Intermittent fuel delivery causes inconsistent performance
  • No fuel pressure at the carburetor – A simple test is to remove the fuel line at the carburetor and crank the engine to check for fuel flow

Types of Fuel Pumps for the 1982 Datsun 720

1. Mechanical Fuel Pump (Original Equipment)

The factory mechanical fuel pump is the most common replacement for stock 1982 Datsun 720 trucks. For the 1.8L L18 engine (1979-1985), an aftermarket OEM replacement mechanical fuel pump is available that includes new gaskets . For the 2.0L L20B engine, the GMB Mechanical Fuel Pump 550-8060 is a direct fit for the 1980 model year 2.0L engine .

Key considerations for mechanical pumps:

  • They are simple, reliable, and require no electrical wiring
  • They produce low pressure (typically 3-5 psi) which is correct for carbureted engines
  • They are sealed units that cannot be repaired – if clogged or malfunctioning, replacement is necessary
  • Always replace the gaskets when installing a new mechanical pump

2. Electric Fuel Pump (Aftermarket Upgrade)

Many owners convert their 1982 Datsun 720 to an electric fuel pump for improved reliability and performance. Electric pumps are available from several manufacturers:

  • Delphi Electric Fuel Pump FD0037 – This is an external electric pump that produces 3 psi with a free flow rate of 27 gph, making it suitable for carbureted engines
  • ACDelco Electric Fuel Pump 06472382 – An electric pump producing 4 psi, compatible with multiple vehicle brands
  • Bosch Electric Fuel Pump 69543 – Specifically listed for Datsun Nissan 720 models from 1981-1986

Electric pumps offer advantages:

  • They can be mounted anywhere along the frame rail
  • They provide consistent fuel pressure regardless of engine speed
  • They eliminate vapor lock issues common with mechanical pumps in hot weather
  • They require proper wiring and a relay for safe operation

3. Complete Fuel Pump Assemblies

For the 1980-1986 720 models, complete fuel pump assemblies are available that include all necessary installation hardware. These assemblies are designed for specific engine sizes:

  • 1.8L L4 engine – Fuel pump assembly for 1980-1986 Nissan Datsun 720, compatible with Base, Deluxe, and King Cab submodels
  • 1.5L engine – Fuel pump assembly specifically for the 1980-1986 Nissan Datsun 720 King Cab with the 1.5L engine
  • Z20, Z22, Z24 engines – A universal fuel pump designed for the 1980-1986 Nissan Datsun 720 Ute and D21 models

How to Diagnose a Bad Fuel Pump on Your 1982 Datsun 720

Before replacing the fuel pump, it is important to confirm that the pump is actually the problem. Follow these diagnostic steps:

Step 1: Listen for the pump – On electric pumps, turn the key to the ON position and listen near the fuel tank. You should hear a humming sound for 2-3 seconds as the pump primes . If you have a mechanical pump, you won't hear this sound.

Step 2: Check for fuel flow – Disconnect the fuel line at the carburetor and place it in a container. Have an assistant crank the engine. Fuel should spray out in pulses if the mechanical pump is working .

Step 3: Check the fuel filter – A clogged fuel filter can mimic fuel pump failure. Replace the filter first if it has not been changed recently .

Step 4: Verify fuel pump fuse and relay – For electric pumps, check the fuse and relay. If the fuse is blown, replace it with one of the same amperage .

Step-by-Step Fuel Pump Replacement for the 1982 Datsun 720

Replacing the fuel pump on your 1982 Datsun 720 is a manageable DIY project. The 1982 model year is covered by the official Datsun Pick-up Model 720 Series Service Repair Manual, which provides detailed instructions .

Tools and Materials Needed

  • Wrench set (metric sizes)
  • New fuel pump with gaskets
  • Fuel hose plugs
  • Screwdriver set
  • Safety glasses and gloves
  • Fuel container
  • Shop rags

Removal Steps

1. Safety first – Park the vehicle on a level surface, engage the parking brake, and disconnect the negative battery cable to prevent accidental sparks . Work in a well-ventilated area away from open flames.

2. Relieve fuel system pressure – For mechanical pumps, this is usually not necessary. For electric pumps, remove the fuel pump fuse and run the engine until it stalls .

3. Disconnect fuel hoses – Detach the fuel inlet and outlet hoses from the pump. Immediately plug the hoses to prevent fuel spillage .

4. Remove the pump – For mechanical pumps, use a wrench to unscrew the nuts and washers securing the pump to the engine block. Carefully lift the pump away from the crankcase . For electric pumps, remove the mounting bolts and disconnect the electrical connector.

5. Discard old gaskets – Remove and discard the old joint gaskets. If an insulator is present, keep it for reuse .

Installation Steps

1. Clean mating surfaces – Thoroughly clean the surfaces of both the pump and the engine block or crankcase where they meet .

2. Install new gaskets – Position new joint gaskets onto the cleaned surfaces.

3. Reattach the pump – Secure the fuel pump back onto the engine using the nuts and washers. Ensure it is tightly bolted into place .

4. Reconnect fuel hoses – Attach the fuel hoses back to the pump securely. For electric pumps, reconnect the electrical connector.

5. Test for leaks – Reconnect the battery, start the engine, and check for any fuel leaks around the pump and hose connections .

Important Considerations for Your 1982 Datsun 720

  • Engine compatibility matters – The 1982 Datsun 720 came with multiple engine options. The L18 engine uses a different pump than the Z22 or Z24 engines . Always verify your engine size before purchasing a replacement.

  • Fuel pump location – In the 1982 Datsun 720, the mechanical fuel pump is located on the side of the engine block. If you are converting to an electric pump, mount it near the fuel tank for push-type operation or near the engine for pull-type operation.

  • Fuel filter replacement – Whenever you replace the fuel pump, it is highly recommended to also replace the fuel filter. A clogged filter can cause premature failure of the new pump .

  • Keep the tank full – After installation, keeping the gas tank at least one-quarter full helps cool and lubricate the fuel pump, extending its life .

Why a Quality Fuel Pump Matters for Your 1982 Datsun 720

The fuel pump is the heart of your truck's fuel system. Without proper fuel delivery, the engine cannot run correctly. A failing pump can cause a range of problems from poor performance to complete breakdown. When replacing your 1982 Datsun 720 fuel pump, investing in a quality replacement part ensures reliable operation and peace of mind on the road.

Common failure modes include:

  • Diaphragm rupture (mechanical pumps) – Causes fuel to leak into the engine oil
  • Check valve failure – Allows fuel to drain back to the tank, causing hard starting
  • Electrical failure (electric pumps) – Complete loss of fuel delivery
  • Contamination – Debris in the fuel system can clog the pump

Recommended Fuel Pump: KEMSO High Performance Fuel Pump

When it is time to replace the fuel pump on your 1982 Datsun 720, choosing a high-quality aftermarket brand makes all the difference. KEMSO fuel pumps are high-performance, OEM replacement units engineered to match or exceed original equipment specifications for flow rate and pressure. Every KEMSO pump comes with a lifetime warranty, giving you total peace of mind for as long as you own your vehicle .

KEMSO pumps are designed to handle modern fuels, including gasoline and ethanol-blended fuels like E85, using Viton O-rings and components that resist ethanol-related degradation . Each pump is individually tested for flow and performance before leaving the factory, ensuring you get a product that works right out of the box .

For a wide range of applications including cars, motorcycles, ATVs, UTVs, and personal watercraft, KEMSO offers pumps at an affordable price point of just $79.98 for many models . Visit KEMSO Racing today to find the exact fuel pump for your vehicle: https://www.kemsoracing.com/

Final Thoughts

Replacing the fuel pump on your 1982 Datsun 720 is a straightforward repair that restores proper engine performance and reliability. Whether you choose a mechanical pump to maintain originality or upgrade to an electric pump for improved consistency, the key is selecting the correct part for your specific engine and installation. Always follow safety procedures, replace gaskets and filters, and test the system thoroughly after installation.

For more information on finding the right fuel pump for your 1982 Datsun 720 or any other vehicle, visit https://www.kemsoracing.com/ to browse their complete catalog with detailed fitment information and customer reviews.


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