Why wont my Suburban not start on first try?

What is your question?

Just bought 2004 Suburban 1500, 143,000, well maintained, but won't start on first try. Many times it will start on the second or third try. We just replaced fuel filter, still doing same thing. Occasionally will start on first try but 90% of time it takes a second or third try and then it sputters like it may die out. What do I check next?