Quadrajet carbs have a fuel filter element behind the fitting that the fuel inlet line screws in to. First make sure it has one in it,second probably wouldn't hurt to replace it since you've got it apart. It's worth mentioning that there were 2 different length filters. Match the old one,or take the threaded housing with you to the parts house to make sure you get the right one.most importantly,it should have an anti drain back valve in the filter you install .that could be your problem of why it's losing its prime to the fuel bowl.
