'93 5.0 fuel problem?
 

My '93 5.0 which has a new fuel pump and fuel tank takes spells where it loses all power and will only go 5mph. Sometimes it will die. Usually if it sits a few minutes its okay again. It acts as if it has some type of fuel blockage but I can drive 500 miles and have no problem and then it starts. Usually when taking off from a stop. Any ideas?