check ignition
lack of fuel
you can but it wont stay running if the battery is dead
dirty carb bowl or water in the carb
bad alternator, dead battery.
Check the idle sensor if you have one.
have a pontiac 6000 2.5 motor and it wont stay running
Bad starter motor?
Mine wont start because the engine is out on the rebuild stand right now, Yours I have no idea
Type your answer here... It could possibly be the ignition switch.
The Optispark distributor is notorious for causing this problem.
Start by checking your fuel filter.