Thunderbird Fuel and Water Pumps

Electric Fuel Pump

When the car sits for over a week at a time, the fuel bowl in the carburetor tends to drain. Since the car has a mechanical fuel pump, the engine must be cranked for a while for fuel to reach the bowl and start up. This is a problem for two reasons. First, the engine wear during cranking is greater since the engine is not spinning fast enough for oil pressure to build. Those 20 seconds of cranking is causing a lot of unnecessary wear to the internal engine components. Second, this goes against my objective for the car to have a more modern "feel" to it. Since my wife will also begin using the car, it must "just work". Fixing this issue means replacing the mechanical fuel pump with an electric pump.

Plans are to eventually replace the carburetor with a fuel injection unit. Fuel injection requires a high pressure fuel pump, while a carburetor requires a low pressure pump. Electric pumps are cheap enough to install an interim low pressure pump until I am ready to upgrade to the fuel injection unit. I paid about $20 at the local auto parts store for this unit.

Figure 1 - Electric Fuel Pump

Normally the electric pump should be placed as close to the fuel tank as possible. Mechanical fuel pumps are designed to pull fuel and are located close to the destination, the carburetor. Electrical fuel pumps are designed to push fuel and are located close to the source, the fuel tank. However, I ran across an electric pump conversion kit which used the unused clutch linkage mounting holes for the pump. This is located in the engine compartment. The instructions are HERE . Although this is not optimal, I decided to give it a try. This is much easier to mount and minimizes the amount of modification to the fuel lines. So far it seems to be working fine.

The pump relay is placed on the left fender well next to the brake booster. Figure 2 shows the pump relay before the brake booster is installed.

Figure 2 - Fuel Pump Relay On Front Left Fender

There is obviously a fuse (not shown) in the circuit as well. A 10 amp fuse seems to work fine with this pump.

Water Pump (Part 2)

In a previous blog I mentioned I am planning on upgrading the water pump since I had to remove it anyway to replace the old power steering pump bracket. At the time the new pump had not arrived. I have it now, it is shown alongside the old pump in Figure 3.

Figure 3 - Old and New Water Pump with Additional Vanes

The new pump (left) has additional vanes on the back of the impeller for higher coolant flow. An article I once read (but can no longer find) showed data indicating this modification actually worked. Another popular modification, a water pump baffle, did not work. In fact the baffle impeded the coolant flow rather then enhancing it. When I removed the old water pump, I found the previous owner had installed a baffle. This could be the cause of my overheating problems. I may not have needed the new water pump after all, removing the baffle might have been enough Oh well, I have the new pump now so I might as well use it. I will not know for sure if my (hopefully) better cooling is now due to the removal of the baffle or the enhanced water pump. As an engineer I would like to know, but it really does not matter. As long as the issue disappears I will be satisfied.