i'm still new to the stang and don't know much. over the last month or so when i start it mostly when it's cold outside it will stall on the first try. and yesterday i went to start it and it won't run at idle period. if i give it a little gas it will run fine but soon as i let off the tach falls to zero and starts sputtering and cuts off. other than that nothing is wrong. anybody know what this could be?