This is what I do in the cold, when the choke doesn't close properly:
Pump the gas two or three times and then immediately take your foot off the gas and hit the starter. Just as it catches, you can give it a little more throttle. This procedure acts like a choke by creating a rich mixture and restricting the air. This works best on a good old v8.
Another little trick is to let go of the starter as soon as it fires the slightest amount. On a standard conventional ignition, the lack of starter draw allows the system voltage to recover and allows for a hotter spark.
