On my dad's 93 LX, the moment you hit the throttle there is a slight hesitation like it wants to go but is restricted. After stepping on the gas for about 2-3 seconds, it finally wants to go. Pretty dangerous. He's already replaced the fuel filter, checked plugs, etc. right now he is in the process of replacing the TPS. Your thoughts/ suggestions? Besides get rid of a 4 cylinder "Mustang", I've already told him that a bunch of times. lol He's actually trying to sell it, that's why we're trying to fix it.

 

TPS would be where I'd start. You can test the current one on the car by checking the reistance if its a rotary style, should increase linearly and start out at about .9V, or is it .6 with the plate closed. Or at least thats what its like on my car.