Okay everyone, I got the new motor in my car, see sig. I had an LG4 before. Now here is what I don't understand, I switched to a 350 mechanical fuel pump on the motor. However with the motor off and the key turned to the accesories the carb bowls were filled and i hear this whirring sound at the back of my car. Am I still pumping fuel? Or is this sounds okay? and if I am pumping fuel, is this sound okay?

 

'87 LG4's had both an electric pump in the tank and a mechanical pump on the engine. The intent was to reduce vapor lock.

You should be using a mechanical pump with three ports: inlet, output to the carb, and return. The return is important to avoid over-pressurizing the carb needle & seat valve.

 

Check out your original post..I rounded up a bunch of help for ya...
https://www.thirdgen.org/techbb2/sho...478#post706478 and here..
https://www.thirdgen.org/techbb2/sho...hreadid=111680