Roastedchicken

Hi guys i have an 89 ta with 305 tpi. Tried to leave for work yesterday and car wouldnt fire . it would crank but not fire. I matted the gas and it fired up but when i let off gas it died. i waited 1/2 a minute turned on key and cycled pump and it started, so i headed to work (cuz i was late). Made it most of the way and at a stop it began idling down real hard. I made it to work and shut off car. Refired it and it wouldnt start, i waited, let the pump cycle and it fired . It does this every time now .And the car is starting stumble while driving. Afriend told me its injectors but im hoping you guys will tell me its a missing screw or something. Any help would be greatlyappreciated.