1992 Jimmy

Gotta 1992 GMC Jimmy vortec.
at start up and the first couple of minutes it runs fine. Once it warms up a little the car backfires through intake, runs very rough and shut itself off when trying to give it gas, but idles fine.

any help would be great.

Well, first check for coeds and see what you get. But if its running good when clod and then gets bad soon after, it sounds like its in open loop and it runs alright, but as soon as your getting into closed loop, your having problems. When was the oxygen sensor last replaced?