Why wont my Pickup start?

So there was no sighns of going bad. It was running strong. The only problem with it was it leaked oil. But I never let the oil get dangerosly low, I always kept it in check. It just died. I have sence replaced the fuel pump, rebilt the throttle body( W/ new injecters), got a new battery for it, replaced the spark plugs, and reset the timing. Now, its getting spark, however fuel is bearly getting past the injecters. If I dump a lil fuel into the throttle body it will spudder and turn over for a few moments then its dies out when the fuel is gone. Im a mechanic myself, well kinda, im still in training but ive never had a problem I couldnt fix untill this. So dont cut back. Talk full on mechanic il understand it