my cad catera will start then die if i turn key off then start runs afewsecon on 2001 Cadillac Catera

i have changed fuel pump crank sensor i can get it to run at idol with starting fluid if iturn key off and try restart it will start for afew seconds codes po100 u2108 any sugestions greatly app thank you

Asked by for the 2001 Cadillac Catera