my ford E#350 is runing ruff and it will nut stay runing

It could be many things, unfortunately and without experiencing the problem first hand or being able to do some basic diagnostic tests its hard to say. It could be engine mechanical, lack of fuel pressure or delivery or lack of sufficient spark/ignition. Start by checking the basics, ensure the ignition system and spark plugs are in good order, make sure there are no vacuum leaks.There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online