1995 Chevy Astro

Engine won't start unless I put a little gas through air intake then it will run but the idle speed goes up and down. And if you throtle the engine it dies or if you let it keep idling it will eventualy die and other times it runs to rich runs ruf and bloes black smoke. I have replaced the fuel pump and filter and the module that goes on the butterfly shaft (throutle control modual) not sure what it is called