when u say jump, u mean jerk?? it could be a number of things.. does it idle rough? making the car shake when ur at a stop? if it does, then its highly possible u have a vacuum leak.
the hard starting could be many things too.. could be damaged HT leads or even a duff coil pack.. (these would also contribute to the jerking).
another thing that could cause hard starting is a leaking fuel pressure regulator, but it would be most difficult to start the engine when its hot if it is this component thats the culprit. however since you say its coupled with jerking i think its probably not this..
first of all id say, change your fuel filter, change your air filter, check your HT leads, change ur spark plugs.. basically do a full tune up first.. then if u still have problems, then we should look at things like the coil pack and also look for vacuum leaks..
is the engine light on and are there any codes stored?