1998 GMC C1500 truck won't idle,runs for 5 seconds and died

my truck runs for 5 seconds and than dies,but the fuel puulatermp keeps running after i shut it off and take the key out of ignition,the pump keeps running for about 15-20 seconds,i had a guy change my steering colume,it was running goood befor that,i changed my fuel pump and fuel regulator