Does anyone know how much pressure would be coming from the stock fuel pump of a 1974 with a 350 SB (L42)?

 

Between 5 and 7ish.

 

I broke the original fuel pump taking the old engine out of the car a few years ago, at the start of my restoration, so I bought a "like for like" replacement for the new engine. I didn't reuse the old Rochester Quadrajet either and have installed a new Edelbrock 1806S carb instead.

I tried starting the new engine for the first time this past weekend but the new carb is flooding like crazy as the engine cranks. I have to pinch off the fuel line from the pump to get the engine to start. It will then run and burn off the fuel in the carb but as soon as I release the clamp on the line from the fuel pump the fuel pours out the top of the carb and the engine quits.

The restoration included all new fuel and return lines to/from the tank as well as new Russel hoses, fuel filter and fittings from the fuel pump to the carb.

Is it possible that the fuel pump is over-pressuring the carb and forcing the float valves open?

 

More likely that the float and needle valve is stuck open on your new wondercarb.

 

 

I did take the top off the carb and found the metering rods a bit sticky and the two floats out of adjustment. These issues have been remedied as per owners manual yet the carb still floods.

The owners manual also says max fuel pressure for this carb is 6psi and that the pressure should be set at 5.5psi with a regulator if high. That's why I was thinking the fuel pump might be my issue. Your thoughts??

 

your needle and seats are bad then, they're not holding

 

My stock pump is running between 7 and 9 psi. These Edelbrock carbs do not like pressures over 5.5. I just received my pressure regulator and will be installing it after I get the car shot in primer (bare glass and grease/gas = very, very bad).

Same situation - new(er) carb, kitted and adjusted 100% according to the Edelbrock manual for the carb. Mine will run, but has flooded out and I'm not taking chances with a new motor. Hoping the regulator will solve it for good.

http://www.summitracing.com/parts/HLY-12-803/

Adam

 

I agree with Mike Ward on this too! I installed a high volume electric fuel pump with out the return line hooked up! Don't do this dumb trick! The pressure built so high on my Holley, it too, would flood out! To fix this, I installed a 1/4 inch return line after the pump and before carb! My pressure guage on the carb line reads 5.5 to 6lbs always!