when you stop on a hill going down and take off it will smoke

It could be many things but if it blueish black smoke and you see a cloud of smoke on initial start up in the morning or after prolonged idling (say in traffic or at a stop light), on accelerating away from this king of stop it is usually a sign of worn valve guides or seals. Get a friend to drive the car allow it to idle then tell him accelerate, follow him on the freeway and see if the engine smokes under load and whether the smoke is blue (oil) or black (excess fuel).