Fuel Pump Replacement: Tank Or 74 Mgb?

The fuel pump in a 74 MGB is located under the vehicle, on the passenger side, between the fuel tank and the battery box. It is possible to replace a faulty fuel pump with an electric one, but this requires careful consideration of the pressure and location of the new pump. A noisy fuel pump may be a symptom of a failing pump, but this can be mitigated by mounting the pump on a rubber motor mount isolator.

Fuel pump location

The fuel pump on a 74 MGB is located under the vehicle, on the passenger side, between the fuel tank and the battery box. The pump can be accessed by removing the cover in the trunk, where the 12V supply can be found.

Some owners have replaced the standard fuel pump with an electric pump, which can be mounted in the same location, or near the carbs and fuel filter. It is recommended that these pumps are mounted as close to the fuel tank as possible, to reduce the amount of suction required to draw the fuel in and to minimise the possibility of vapour lock in the engine bay.

There is also the option to install an in-tank fuel pump, which has been done on some Ecotec-powered MGBs. This requires a returnless fuel system.

Fuel pump replacement

If you are experiencing fuel issues with your 1974 MGB, it may be time to replace the fuel pump. Before you do so, however, there are a few things you should check.

First, check the fuel tank for any signs of rust or corrosion. This can be caused by condensation forming inside the tank when the outside temperature cools down. If the tank is rusty, it may need to be cleaned or replaced.

Next, check the fuel lines for any blockages or leaks. You can do this by blowing compressed air through the lines or by using a fuel line pressure tester. If the lines are blocked or leaking, they will need to be replaced.

Now, check the fuel pump itself. The fuel pump on a 1974 MGB is located under the vehicle, on the passenger side, between the fuel tank and the battery box. If you hear a ticking sound when you turn the key, the fuel pump is working. If you don't hear a ticking sound, the fuel pump may need to be replaced.

You can also try cleaning the connections on the fuel pump and checking for power with a DVOM (digital volt-ohmmeter). If there is no power, the issue may be with the wiring or the fuel pump relay.

If you determine that the fuel pump does need to be replaced, there are a few options available. You can purchase a new or refurbished OEM fuel pump, or you can upgrade to an electric fuel pump. Electric fuel pumps are more reliable and can be purchased from a variety of manufacturers, including SU, Facet, and Herko.

When installing a new fuel pump, be sure to mount it as close to the fuel tank as possible to minimize suction and reduce the possibility of vapor lock. Additionally, consider using a rubber motor mount to isolate the pump and reduce noise.

Finally, always refer to a qualified mechanic or repair manual for specific instructions on replacing the fuel pump on your 1974 MGB. This process can be complex and may require specialized tools and knowledge.

Fuel pipe replacement

When it comes to the fuel system of classic cars like the 1974 MGB, there are a few potential issues that owners may encounter. One common problem area is the fuel pump, which can fail or become inefficient over time. In some cases, it may be more advisable to replace the fuel pump with the tank rather than attempt a standalone pump replacement. This is because the original fuel pump on the MGB is located inside the fuel tank, and accessing it can be a complex and time-consuming task.

If you're considering a fuel pump replacement on your 1974 MGB, it's important to inspect the fuel lines and hoses as well. These components are crucial in ensuring a consistent and safe fuel supply to the engine, and they can become brittle, cracked, or clogged over time. A full fuel pipe replacement is a job that many MGB owners undertake as part of their car's maintenance, and it can help ensure reliable performance and reduce the risk of fuel leaks.

The process of replacing the fuel pipes on an MGB is a detailed job, but with the right tools and knowledge, it can be completed successfully. The first step is to safely drain the fuel tank and disconnect the battery to avoid any potential sparks. Next, remove the rear seat and interior panels to access the fuel lines and pump. Care should be taken to properly seal and dispose of the old fuel.

With the interior panels removed, you'll have better access to the fuel lines and pump. The original fuel lines were often made of steel, and these can become corroded and clogged over time. It's recommended to replace these with modern, high-quality rubber hoses, which are more flexible and less prone to cracking. When replacing the fuel lines, it's important to use the correct type of fuel hose and to ensure that all connections are secure and leak-proof.

As you work on the fuel pipe replacement, inspect the fuel tank for any signs of corrosion or damage. If the tank is in poor condition, it may need to be replaced or professionally repaired. This is also an opportunity to consider upgrading to a stainless steel fuel tank, which offers improved corrosion resistance compared to the original steel tanks.

Finally, when reinstalling the new fuel pump and lines, take care to ensure that all connections are tight and secure. Use appropriate fuel-resistant sealants or thread tape to prevent leaks. Once the fuel system is reassembled, you can refill the tank and reconnect the battery. Always perform a final inspection to ensure that there are no fuel leaks and that the system is functioning properly.

Electric fuel pump

There are several types of electric fuel pumps, including:

• Positive displacement "roller cell" pump: This type uses rollers mounted on an offset disc that rotates inside a steel ring. Fuel is drawn into the spaces (cells) between the rollers and pushed along from the pump inlet to the outlet.
• Gerotor pump: This design is similar to that of an oil pump and uses an offset rotor to push fuel through.
• Roller vane pump: This type uses vanes instead of rollers to push fuel through the pump.
• Turbine-style fuel pump: This type has an impeller ring attached to the motor, with blades in the impeller that push the fuel through the pump as the impeller spins.

When choosing an electric fuel pump, it is important to select one that can generate the same operating pressure and deliver the same volume of fuel as the original pump. Using the wrong pump can cause drivability problems due to variations in fuel pressure or flow.

In addition to the type of pump, there are also different mounting options. Electric fuel pumps can be mounted inside or outside the fuel tank. Some vehicles may even have two fuel pumps: a transfer pump inside the tank and a main fuel pump outside. Mounting the pump inside the tank helps to muffle the buzzing noise produced by the electric pump motor, and immersing the pump in fuel helps lubricate and cool the pump motor.

When replacing an electric fuel pump, it is important to consider the cost of the pump itself as well as the labor involved in the replacement. A new electric fuel pump may cost from $100 to $300 or more, depending on the application and whether you are buying just the pump or the complete fuel pump module assembly.

In terms of maintenance and troubleshooting, it is important to keep the fuel tank at least 1/4 full to prevent the pump from running hot and shortening its life. If the pump fails, there are several ways to diagnose the issue, including listening for pump noise after turning the ignition key on and checking for fuel pressure at the engine fuel rail.

In-tank fuel pump

An in-tank fuel pump is a component used in liquid-fuelled engines, such as petrol or gasoline engines, to transfer fuel from the fuel tank to the carburetor or fuel injector. The pump is placed inside the fuel tank to prevent the high pressure from causing the fuel to ignite inside the pump and exploding.

Some signs that your in-tank fuel pump may be failing include:

• Whining noise coming from the fuel tank
• Engine sputtering or surging
• Difficulty starting the car
• Loss of power under load
• Reduced gas mileage
• Stalling at high temperatures

If you suspect your in-tank fuel pump is not working properly, it is important to have it inspected and replaced if necessary to avoid poor fuel economy, engine misfires, or severe engine damage.

Frequently asked questions