its hard to explain..

you know how your in first gear from a stop.you press the gas to go..still in first gear, your in high rpm say like 5k..than you let go of the gas the car jerks forward right..well thats what happened to me when i was on the highway and i was in 5th gear and the problem is i was pressing the gas and it felt like i let go of the gas and the car jerked forward..its like i would stop accelerating but my foot was actually on the gas still.i have a 92 max with ve engine..i just changed the timing this past weekend because i advanced it awhile ago.i think it is the timing because the car has been sluggish under acceleration..especially when i had my AC on..any suggestions would be appreciated...thanks...