If you are buying new or rebuilt pumps from your FLAPS I'd certainly take them back for exchange. If your truck sat for a long time before you acquired it one possibility is there was old gas in the tank when you put fresh gas in it. What that can do is put varnish from the old gas into suspension in the fresh gas. When you let it sit and things dry out it can turn back into varnish on the small one way valves inside your fuel pump which will cause it to not pump. If that's the case you'll need to drain, remove and clean your tank. That process has been discussed here many times. A search will get you hours of reading.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.