sorry, im new here, didnt know where to put this.

so my fiance owns a 94 3000GT and as of today it is sputtering. i drove it around the block and when in park it idles fine but as i was driving it the whole car was shuddering and you could feel the engine sputtering. felt kinda like it was gonna stall but it didnt. all i remember is that when the vacuum line to the map sensor on my jeep broke it cause the jeep to idle rough and run rich but it doesnt smell liek its running rich and as i said its not idling rough. im thinking something to do with the fuel system in direct relation to drive and reverse? any advice or ideas would be helpful.