Help! I have a 1972 Fire Truck with a V8 534 CI engine. I believe the electric fuel pump, mounted out side the fuel tank 25' from the carb is bad. The numbers off the pump are:

Transister Fuel Pump
12V Grnd
Unit No A6988
U-Shin LTD

When I remove the fuel lines and connect a fuel line into a gallon of gas (in) and turn the key, I hear the sound of the plunger going up and down but no gas is exiting the pump.

Anyone know anything about this pump or what the correct PSI fuel pump should be?

Thank you, Jerry

 

Carb'd motors should run under 15psi, real (direct injected) gas fuel injection should run around 38-45psi (stock) and the throttle body type can run anywhere from 14-44psi.

Because it says transistor, I'd look closely if the pump or regulator has a return line. I am not sure what is available in low pressure fuel pumps, but fuel injection has two sub-types, return and returnless. Returnless, the pump is turned on and off as need to keep pressure and this might be hard on a pump not rated for returnless operation. Return is easy, the regulator dumps the excess back into the tank to get recirculated.

Holly, Carter and pretty much any other carb manufacture will make low pressure pumps, aeromotive and many others make high volume, high pressure pumps.

 

Thank you. I agree. My engine has a carb and is not fuel injected. There is no fuel regulator or return line. I am told the PSI should be between 6 - 9 PSI. I found the manufacture U-Shin is still around and in Japan. I am trying to find a US distributor for U-Shin. I am confident the fuel pump is not pumping. There is also no suction in the inlet. The pump has one IN and one OUT 5/16" fuel line connectors.

 

Once you get the flow rating and pressure, you can spec out an aftermarket pump and add a regulator to set your pressure.