91 Cavalier RS 3.1 Wont stay running

91 Cavalier RS 3.1 wont stay running. changed fuel filter, coil pack, map senser , idle senser, throttle senser. also checked fuel presure at the the fuel rail. no codes came up on the scanner. and change spark plugs and wires. Im running out of thing to look for . Can someone help me please.

When does it stall? Start and die immediately, run for a few minutes, run until it gets hot? How does it die? Sputter and die, just shuts off like you turned the key off, idle lower and lower until it dies?