hey guys im having a hard time keeping my Z running, its a 1975 280z. ever since one day when it was really cold she wont stay running unless i keep the throttle open a little, ive checked my EFI and it seems ok and ive look at my plugs and wires and the timing is in and ive checked the seals on the valve cover, injectors, and oil filler cap. im running out of ideas any help would be much appreciated.