Electric Fuel Pump Conversion
NOTE: The circuit shown is going to be obsolete, please see my engine bay re-wire article for more information.

One critical update I made was eliminating the stock mechanical fuel pump and replacing it with an electric fuel pump. I found out the hard way that the stock mechanical fuel pump would pump fuel to the carburetor at upwards of 10 psi, while the Weber wants an input fuel pressure of ideally 3 psi but absolutely no more than 5 psi. Needless to say, I had some carburetor flooding problems when the mechanical pump would force fuel past the needle valve. The electric fuel pump I installed is a self regulating pump that will do 1 to 5 psi, so now the Weber carburetor is happy. I tucked the fuel pump away just behind the alternator on the fender and was able to use the existing metal fuel line from the tank without modification.

The fuel pump is controlled by a simple relay and transistor circuit protected by diodes and housed in a modular relay box I pulled from a Nissan and bolted to the driver's side fender. I like using these Nissan relay boxes, they come in many size and relay position variations and use a modular relay socket system so you can figure out what relays you need and then find a Nissan that has them and pop the socket into the relay box. They seem to be most common in 1990's and early 2000's Nissan models (perhaps even some Infiniti models as well) before Nissan started combining the relay box with the fuse/breaker box.

We also found a momentary push-button switch at Pick-n-Pull that is marked "Fuel" (pulled from a Lincoln Town Car) and I wired it in as a fuel pump priming switch. I found that when the pump isn't running, it tends to allow back flow of fuel to the tank. So rather than sit there cranking the engine until the fuel pump starts pumping fuel, I just added the primer switch. Press and hold until the clatter of the fuel pump quiets down and you are good to go!