1995 Other GMC Models truck sometimes stalls

Hi I have a cmc pickup 4x4 sometimes it goes dead and it is fuel injected and I have to keep pumping gas pedal to get it to start back up it act like it not getting gas but after it starts back up it runs fine mabe drive it a month before it does it again may be 3 days the check eng light comes on sometimes while driven but when I turn truck of it does not come back on after driveing sometimes it comes back on what could cause this