have running problems with 88 ford mustang?

[Deenie]

ok i own a 88 mustang 2.3l turbo and it is running bad when i go out to start it i have to keep my foot on the gas to keep it running but after i drive it for a while and stop and then go start it it will start. to day i was driving on the highway at 70mph and they car just shut of then it started back up. i tried seafoam and it did not work but what could it be it just started doing it a few days ago, and some times it will jerk when i am driveing, please help me