Fuel Restriction

[Stroken49s]

I have a 2000 7.3L work truck that has been missing for quite a while. I decided to put new Injectors and glowplugs in it hoping that would solve the problem, well it didnt. The passanger side of the block, the back 3 injectors arent pumping any fuel. We put in a new computer we got from ford for the injectors that goes behind the drivers side fender and they still aren't pumping any fuel.. When we hook up a tester light it shows it hitting, so my guess is that there is a fuel blockage somewhere, When you first start it up after sitting for a while it runs fine for about 4 secs, my guess is the fuel is slowly getting by and making its way to the injectors. Any thoughts on how to clear the lines, and the line in the head>????