Stalling 1988 Chevrolet Corsica

This car stalls after running for awhile; it’s a random intermittent problem. We put a new fuel filter in and checked all plugs and wires and nothing seems to be fouling. What are other possibilites to this problem? It’s a v6 2.8 liter fuel injected engine.

How and when does it stall? Does it stall suddenly, or does it stumble to a stall? Does it stall when cruising, or when slowing, or when accelerating? Does the engine stumble during acceleration? Other details?
Does it re-start easily, or is it difficult?

Our car when it stalls it stumbles feeling like I ran over a bump while I’m cruising. The engine has been warming for at least 10 minutes before driving. The engine does stall during acceleration. The check engine lights don’t come on until the car has died. There has been a few times when it has not run for approx. 24 hrs, and when I go out to start it, the car tries to turn over, but it makes a clicking sound and won’t start. When this has happened it’s a few days before the car will even start again. When it has stalled on me sometimes it would start right back up, but more recently it will not start for at least a couple of hours. The battery and cables have been replaced as well as the fuel filter. The plugs and wires do not seem to be fouling. There does not seem to be a pattern other than the engine being warmed up as to when the engine will stall.

That seems like two different problems: a fuel problem and an electrical problem.
MEASURE the fuel pressure with a test gauge. Test with the engine at 2000 rpm, with the gear shift in DRIVE. If the fuel pressure doesn’t hold, test the fuel pump (make sure it’s getting 12+ volts).
The starting problem seems to be low voltage to the starter solenoid. The start circuit goes through the ignition switch, neutral switch, maybe another switch, to the starter solenoid.At one of those places, a poor connection could be causing the voltage too low to make the starter solenoid turn on. The starter solenoid sends battery power through the starter. Check the voltage along that start circuit. Just changing parts is possible, but expensive.