96 GMC Jimmy Hard Start

96 GMC Jimmy with 4.3L hard to start hot or cold, will start with either, or you have to cycle the key approx. 45 times to get it to start. But if you boost it even if the battery is not dead it will start up right away with no either or cycling of the key. In other words as long as I put a boost on it, it will fire up right away with no hesitation or problems. Please help some say fuel regulator, some say fuel pump, some say the starter could be drawing to much power to allow fuel pump to run properly. It does not make any sense to me or my mechanic that if you boost it, it starts rightaway.