First off, I am new here..I hope someone on here can give me an idea. I am having fits with a bronco I am working on. I am upgrading, should say down grading the fuel system on a bronco for a customer of mine. He had a Holley projection on it, but wanted to go back to a carb. So I Changed it to a 600 vac sec holley. Put a mechanical fuel pump back on the motor. Now I cant get fuel to the motor. I installed a fuel filter where the old projection fuel pump was. The pump is pulling vacuum at the filter and I can pull fuel out of the tank with a vacuum pump. But when it is all hooked up I cant get it to pull fuel. Any ideas why the I cant get fuel to the motor.. Thanks in advance.