I hope some one can help me I have a 1986 Ford Mustang GT with a 5.0

Fuel Injected  system the person who owned it before me did not know what they are doing so they started cutting out vaccum lines and the remove the smog pump and they plug things can some one give me a list of things I do not need under the hood and will not effect the way it drives. Now it drives but the idle is off it stalls some times and it is not a steady the fuel pump you can hear it run when the engine is off but the key is still in the on position some one told me it pumps for 5 sec's and it shuts off but in me case it does not. I still will like to keep my A/C so tell me what I should remove thanks to anyone who replys to me thanks.

I just installed some bassani shorty headers and we removed the smog pump.  We just took out the pump and capped the pipe by the back side of the engine.  By taking out the smog system it will not effect how your car runs,  Other then that i dont know anything else that can be removed.  But a reason your car might be stalling is because it might have a vacume leak.  

it sounds as though someone has wired the fuel pump straight to the ignition??---as far as things you don't need under the hood, i would start with the vaccum lines---the only lines you need are the ones going to the brake booster ,EGR,maybe the fuel pressure regulator,transmission (if you have a automatic),vents inside the car.