Replacing The Fuel Pump On A Big Block Chevy Engine

Replacing the fuel pump on a big block Chevy engine is a straightforward process that can be done with basic tools and some mechanical knowledge. The fuel pump is responsible for delivering fuel from the tank to the engine, and a faulty pump can cause the engine to stall or not start at all. This guide will cover the steps to replace the fuel pump on a big block Chevy, including tips and tricks to make the job easier.

Removing the old fuel pump

To remove the old fuel pump from your Chevy big block, you will need to follow these steps:

Begin by disconnecting the fuel lines that are attached to the pump. Be sure to have a container ready to catch any fuel that may spill during this process. Once the fuel lines are disconnected, set them aside and move on to the next step.

The next step is to unbolt the pump from the engine block. Typically, there are two bolts holding the pump in place. Remove these bolts and set them aside, being careful not to drop them into the engine bay. With the bolts removed, the pump should now be free to lift away from the motor. However, be careful as you do this, as the pump arm is shaped like a bent finger and can get in the way.

As you lift the old fuel pump away, you will notice that the pump pushrod slips down, blocking access for the new pump. At this point, you have a few options to create some space. You can try using a rubber glove for a better grip and slide the pushrod back up into the block. Alternatively, you can use heavy grease or fishing line to hold the pushrod in place while you remove the old pump.

Once you have created enough space, carefully lift the old fuel pump away from the engine, being mindful of the fuel lines and any other components in the area. With the old pump removed, you now have access to install the new fuel pump.

It is important to note that some Chevy big blocks use a mechanical pump, which is moved by a link to the engine cam. If your vehicle has this type of pump, you may need to "prime" the fuel by pumping the gas pedal to start the vehicle. Additionally, the rod between the pump and the camshaft can become uncoupled or seize up, causing the pump to stop working.

Installing a new fuel pump

First, make sure you have the correct replacement fuel pump for your specific Chevy model and engine type. In this case, you are working on a big block Chevy, so ensure the fuel pump is compatible. It is also recommended to have some basic tools on hand, such as wrenches, gloves, and a hose cutter.

Next, locate the fuel pump on the engine. The fuel pump will be connected to the engine by two bolts and will have fuel lines running to and from it. Before removing the old fuel pump, it is crucial to disconnect the fuel lines to prevent any fuel leaks. Once the fuel lines are safely disconnected, you can proceed to unbolt the old fuel pump.

When removing the old fuel pump, pay attention to the pump arm and pushrod. The pump arm is shaped like a bent finger, and as you lift the pump away, the pushrod may slip down, blocking easy access for the new pump. There are a few tricks to manage the pushrod: using heavy grease to slow its descent, rotating the engine to move the rod to its highest point, or using a hack saw blade to hold the rod in place temporarily. You can also use a piece of string or wire to hold the rod in place while you install the new pump.

Now, with the old fuel pump removed, it's time to prepare for the new one. Clean any gasket remnants or residue from the mounting surface, and if necessary, apply a new gasket to ensure a tight seal. Take the new fuel pump and position it against the block, carefully inserting the pump arm onto the pushrod. Secure the fuel pump in place with the bolts.

Reattach the fuel lines to the new fuel pump, taking care to make sure they are correctly connected. Before starting the engine, check for any fuel leaks and ensure all connections are secure. If everything looks good, start the engine and let it run for a while to ensure the new fuel pump is functioning properly.

Finally, you may need to adjust the timing and set the idle speed to optimize the engine's performance with the new fuel pump.

By following these steps, you can successfully install a new fuel pump on your big block Chevy, ensuring reliable fuel delivery and improved engine performance.

Priming the fuel

To prime the fuel, you must first ensure that the fuel tank is full. Then, turn the ignition on and off repeatedly, while simultaneously pressing the gas pedal to the floor. Do this until the pressure in the fuel lines is built up, and you should hear the fuel pump whine. This process should take about 30 seconds. Now, without touching the gas pedal, try to start the engine. If this doesn't work, repeat the process and try again.

It is important to note that you should not pump the gas pedal excessively, as this can flood the engine. Additionally, make sure to check for any fuel leaks during this process. If there are leaks, the engine will not start.

If the engine still fails to start, there may be an issue with the fuel pump or the fuel system. In this case, it is recommended to consult a professional mechanic for further diagnosis and repair.

To avoid issues with the fuel pump and fuel system, it is advised to drive your Chevy regularly and not let it sit idle for extended periods. This will help keep the fuel system healthy and prevent deterioration.

Using an electric fuel pump

Upgrading the fuel system on a retired big-block Chevy is a great way to give it new life. In this guide, we will focus on the process of installing an electric fuel pump as part of that overhaul.

Electric fuel pumps have several advantages over mechanical pumps. They deliver precise, high-pressure flow rates that offer maximum horsepower to the engine and meet stricter emission requirements. They are also smaller, more reliable, and easier to work on.

The first step is deciding what to do with the mechanical pump. There are two options:

• Leave the mechanical pump in place and install an electric one by the tank. This provides a backup in case the electric pump fails, although it is unnecessary as electric fuel pumps are designed to last a long time.
• Remove the mechanical pump and replace it with an electric one. This is a simpler solution, allowing you to upgrade the entire fuel pump system at once and take the opportunity to repair or replace other components.

If you choose the second option, here is a basic overview of the removal and replacement process:

• Uninstall the mechanical fuel pump.
• Cover the hole with a block-off plate gasket and sealer.
• Mount the electric fuel pump near the gas tank, ensuring it is not too high or enclosed, and connect it to the fuel line. The closer the pump is to the tank, the better it will perform.
• Install a filter next to the electric fuel pump.
• Wire the electric fuel pump to the ignition switch.

Some common mistakes to avoid when installing an electric fuel pump include mounting the pump and fuel line near heat sources, such as the exhaust, and failing to install an automatic shut-off system.

By following these steps and avoiding common pitfalls, you can successfully upgrade your big-block Chevy's fuel pump to an electric one, improving performance and reliability.

Sealing the hole in the block

Firstly, you can use a milled billet stop block designed specifically for your engine. These are available from sellers on eBay and can be bolted onto the block using the original pump bolts. Before bolting it on, it is recommended to apply a liquid gasket maker around the edge of the block to ensure a tight seal. This will help prevent any fuel leaks from the hole.

Alternatively, you can use an old fuel pump with the lever removed as a plug. Cut or unscrew the lever from the old pump, clean it thoroughly, and then bolt it into the hole using the original bolts. As with the previous method, applying a liquid gasket maker or sealant around the edge will enhance the seal and further reduce the risk of leaks.

If you have limited access to the front of the engine or are unable to find a suitable plug, another option is to use a strong adhesive or epoxy to seal the hole. Clean the area around the hole thoroughly, ensuring no dirt or debris is present, then apply the adhesive or epoxy to completely fill the hole. Allow it to cure according to the manufacturer's instructions before starting the engine.

In all cases, it is crucial to ensure that the hole is properly sealed before operating the vehicle. Any fuel leaks can pose a serious safety hazard and should be avoided. It is always recommended to have a qualified mechanic perform these types of repairs if you are unsure about any steps or procedures.

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