i have a 93 Mustang GT. i recently had my transmission swapped because the old one was slipping. well the new one shifts fine, but now(its probably been happening for a while didnt try to do it with the slipping tranny) while in gear it wont rev past 2000 RPMs. if its in neutral or park it Rev's fine. the mechanic checked the fuel pressure when he noticed this and at idle it sits at 35, once you gas it the pressure drops to 20. the linkage is a pin off(when im in reverse the shifter says im in neutral, yes it is an automatic :/ ) and the gearing in the new transmission doesnt match the old gearing in the old transmission(the old gearing matched the "Highway Gears" in the rear differential) could these things be causing the car to be in "Limp Mode" or be causing it to just not drive right? like its fine when i drive it like its a semi and barely touch the gas, but the second i give it some gas it accelerates slower. the mechanic thinks it is the fuel pump going out, but i think otherwise. thanks guys.