Problem with the start of my corsa Wind 2000

Hello, well, I tell you my problem .. Make 2 months to buy a corsa Wind Mod 2000 1.6 Naftero. When you buy it, it starts in cold or hot, now it takes to start when it is only cold, hot starts perfect .. I would like to know what happens to you.
Ahh something else, also when I put in contacent to start, turn on a mooring light on the board, they told me that it is common in contact, but what happens is that at times when the engine is running, what does that light mean? Is it a bad thing for the vehicle? Thank you very much

If it is yellow and in the form of the engine it is the check Engine, and it warns you of a failure of the fuel injection system, if it costs the cold starting in cold, it is that it is the engine coolant temperature sensor this gives that failure is not expensive, anyway if the light is turned on even if it goes out after you would scan it to see sience that is, lucky, luck and a few.