fuel system problem

[starchildace]

i have a 95 cutlass ciera.it set up for about a year and the gas tank got rust in it.the tank has been replaced with a clean tank,new fuel pump and new fuel filter.the car ran fine for a couple of day's,then it started spitting and sputtering when you first take off.finally it wouldn't crank at all.put it in the shop 2 day's later and the mechanic said it cranked right up and sat there and ran for a half an hour without a hitch.i talked to him about the lines and/or fuel injector's being clogged,but we agreed that if that was the case it would do it all the time,not sparatically.he's going to check the injector's anyway and he's going to change the fuel pressure relay.does anybody know if we are on the right track here or should we be looking elsewhere?