ZX2 has trouble starting in cold

Well that was the original problem, it go a lot worse and at times she would get stuck at random places with the car just not starting at all. Eventually it would kick over and start but it might take like 20 minutes. On two or three occasions ive had to go pick her up and go back for the car at a later time to see if i could get it to start. I didnt change anything under the hood of the car, i simply pulled the old sending unit, it was only 2 plugs, i can visibly see those plugs and they are plugged in. The pump IS running and i can see the lines get pressure. How would i go about testing the injectors for pulse? do i pull one? When i get home ill check these things out and also check for spark. Im reallyfrustrated with this so i apologize in advance if i get pissed and get a shitty attitude with this. I really appreciate all of the input. Ive noticed that there is some kind of black box, which i assume is the FPR. could this be causing a problem? also i think im gonna throw in a new filter for some peace of mind.