Need help! while driving my tack drops off to zero,engine stops running then comes right back! usually happens while cruising in 5th gear, can happen several times in a span of a few minutes most of times it does`nt happen at all.. the engine usually returns to life own it`s own or I just hit the key and it starts back up! it even happened while sitting at a redlight! car just stops running! but starts right back up with the turn of the key! i know it`s just a matter of time and I`m going to get stranded somewhere! what could be cause this speratic power loss???