1993 Dodge Ram Please please help

It revs fine in park. As soon as I get on the road and accelerate it cuts out, jerks, and sometimes backfires. It also does it while trying to maintain speed. But by far the worst when accelerating. Any type of load makes it do it. I have changed the fuel pump, the in line fuel filter, plugs, plug wires, throttle position censor, and the module on the front passenger side of the motor can't recall it's name. It still does it