You might have a shorted pick up coil wire when you replaced the pick up coil. That way it will work when you hold it in your hand but not when it is on the engine
it was doing this before i replaced the coil in the distributor. i replaced the distributor that morning. the old one would idle down really slow due to sticking weights. put this one in it ran great then hard to start then no start. good thing i dont have alot of hair or i would have pulled it all out.
