Bought an 89 240 sedan for my wife last summer, it ran all summer and fall without any problems, then started stalling on acceleration and left her stranded in the middle of a couple intersections, being a huge safety issue especially with the kids, I've driven it since.

Tuned it up first and ran a bottle of SeaFoam through the intake via the brake booster vacuum line. Replaced the fuel filter, it ran ok for a couple days, then same symptoms, so I changed the main fuel pump under the car, and the fuel pressure regulator. Drove it for a couple days, still intermittent stalls, so I changed the throttle position sensor. Then the fuel pump relay. No change. If I rev the engine up to 2400 rpm, it dies every time. Last time I drove it, it would stall intermittently while moving 45-50 mph, and I was able to keep it going by lightly pumping the gas.

Because it stalls at 2400 rpm and wouldn't run once it came up to temp on a warm day, sounded like the catalytic converter was clogged. Replaced it, no change.

Parts Replaced:
Air Filter
Battery
Spark Plugs
Distro cap/rotor
Fuel filter (main under the car)
Fuel pump (main under the car)
Fuel line from main pump up to the engine
Fuel pressure regulator
Throttle position sensor
Fuel pump relay
Catalytic converter

Not sure which direction to go from this point. Any suggestions are appreciated.