I got a hold of an old Grand Marquis. A 1984 model with a 302cid v-8 and throttle body fuel injection. Its got a huge issue though. It stalls all the time. When I start it it stalls unless i keep a foot on the gas, it stalls when I shift into drive, it stalls when I try to accelerate (engine dies and then comes back sometimes) and it stalls when I come to a stop.

I've replaced the cap, rotor, wires, plugs, o2 sensor, fuel filter, air filter pcv valve and so far nothing has helped. The exhaust on the vehicle is new but there are no catalytic converters, if that might be causing issues. It does better once the engine warms up but not by much. I'd appreciate any help I can get on this one, as the only thing I know it isn't is warped heads.