Did you try replacing the fuel and air filters?

the truck can and probably is suffering from "knocking"
just put a fuel additive in that states with stop the knocking. my car did the same but stopped as soon as i put it in.

I have a 1994 lincoln continental, when I take off from a stopped position my car klonks and draggs before it catches. i had the transmission oil and filter changed also the oil filter changed one day ago. it still hesitates before taking off. also when i am at a stand still it sometimes feels like i have been hit from behing. the car jerks. can anyone help me with a suggestion as to what might possible be wrong. the transmission service mechanic could see nothing wrong with the transmission. please help me thank you. leroy