Whenever I start my car after it's been sitting for over about 8 hours or so (overnight), it will crank and start up fine... but then the rpms drop and it stalls. It's done this for awhile, just tuned it up about 1,000 miles ago with new plugs, wires, cap, and rotor. What could be causing it to want to stall when it's cold like that? It runs very poorly until it's up to normal driving temps.