dies after 20 25 minutes on 1991 Buick Century

we have a buick that stalls out after engine runs an will not restart have had ecm maf crank sensor coil packs and ignition module replaced an the problem still remains. any idea

Asked by for the 1991 Buick Century
Start right back up when it stalls? If not at that time check for ignition fire or spark. If GOOD HOT spark then focus on the fuel system. Need pump pressure reading!
no it will not restart until it has cooled down but yet I have 40psi on fuel an shows great spark
Ok-------- water in fuel. I have no idea! Good luck.