[DAVID GAGNARD]

the internal combustion engine needs three basic things to run:

fuel
fire
compression
since the engine was running fine before,we'll eliminate compression....

start with fuel,make sure your getting fuel,if that checks out,then go on to fire.........
start at the spark plugs and work your way back thru the ignition system..........I'm betting on fire and by going backwards from the spark plugs, you should find the problem....