I've lingered here for a while, but this is my first post. Hopefully someone will have some ideas. I have a '99 C2500 Burb with around 80k miles on the 7.4L. A couple of weeks ago I noticed that on warm starts it will crank and crank before it starts up. Sometimes I'll have to pump the gas pedal a couple times. When it finally does start, there is a bit of black smoke that dissipates quickly. On cold starts, it turns over like a champ. No problems what so ever. Any suggestions? Thanks in advance!