1992 Astro starting problems?

Does anyone have any ideal why my van won`t start right away.? When I try to start it, the starter wants to kick out and make a whining noise. I don`t think the starter or solenoid is going out because it cranks every time. After it makes the noise I wait a second or two and it cranks again. It is like it is not getting gas right away. It has a new fuel pump. If you give it gas to try and start it acts like it floods and then it wants to backfire a little. Then finally it will start up and go. Could it be in the 2 injectors in the carb? Also it makes some kind of knocking noise occasionally. Like something is jarring against something. It is not coming from the motor. I have been over every inch of this van and can not find anything. The ujoints are good and tight. Please someone reply soon.