1991 4x4 Sierra Ignition Problem Help
 

Well heres the deal like idiot i let a redneck work on this truck. He did a tune up and so on to it and we also replaced the distributor with a brand new one. The truck will seem to run fine for a few minutes and then cuts off and does not want to crank back.I also notice a buzzing noise from the distributor that i do not remember from before. Also does anyone know the firing order it is the 5.7 engine. Any help would be appreciated.