my renault megan scenics fan belt broke i put a new on an it wont start?

first its a (deisel reno megan scenic)i noticed a slaping noise and it turned out to be the fan belt in strips it snaped as soon as i opened the bonnet as the engin was running. i was just at the parts shop for some copper washers lucky realy? i got a new belt fitted it tried to start it the hole car shook the engin sounded awfull onece it started then stoped as i let go of the key? thers a weard buzzing coming from the ijector pump when the ignition is on no wires broke or plugs caught as i can see and the light that flashes on the dash for the imobelizer does not come on so i cant try the reset code by pressing the central locking button and it will sometimes fire but when starter is running. ext. any advice will be graitly apreceated thanks

andy
April 2011