engine starts sometime not all the time

just got my 598 bbf a460 headed motor running and man it sounds like it hates chevys! but anyway so I got it ruynning but if I have everything hookup the way msd says it should be be it won,t start but if I run a wire from the red wire from the box it will fire and run for a min and cut off! did all the msd test points just wondering if this box is done for or what? anybody have this problem before let me know! going to buy the grid and box anyway just wondering if this one is died! like to thank lem ,philp, keift for great parts and info on putting this thing together!