'93 Voyager throttle problem.

Hi. I have a '93 Voyager SE with a 3.3 that is acting goofy. Cold or hot, when I give it between 1/4 and 1/3 throttle, it will spit and sputter an carry on until the engine revs up high enough and then the sputtering quits. When it starts doing this, if I give it full throttle, it still pops and bangs until the engine rpms get up there (wherever "up there" is - no tach.) and then it goes ok. Generally, it doesn't occur under average flat driving conditions, but under a load, if I don't get lucky and get past this rpm point, it runs not so too pretty good. I have a new fuel filter to put on it, but the symptom doesn't match starving it for gas. Could it be that the electrical gadgets (air-flow or throttle position sensors) that control fuel mixture on the throttle body be failing? What do I check first? I'd hate to replace all sorts of stuff to find out I just needed one of the parts.
Thanks in advance.

Put the new fuel filter on it if you havent already. Be careful not to let any crap get in the lines. If this doesnt fix it, then it could be the fuel pump. The motor requires a constant fuel pressure to work properly. The pump may be working, but not at full potential, causing the motor to starve for fuel during acceleration or under load. Also check the fuel pressure regulator. This little piece is essential as well. Good luck!