I have a 1991 jeep Cherokee sport 4x4 5 speed i know enough about cars but not too sure about this i was driving down the interstate earlier and jeep was running perfectly fine then all a sudden it started lagging out like it was out of gas so i pulled over it died wouldnt start back it wanted to but no luck thinking i ran out but i was at a quarter of a tank i thought its a older car so it could of just read wrong got a little gas in got it about a a 3rd mile to gas station on my way it was lagging unless i gave it alot of gas but i put gas in still the same thing thinking its the spark plugs or fuel pump i just dont wanna go blowing alot of money on stuff thats not wrong with it any ideas thanks