starting problem

What is your question?

I have a 2003 Lexus LS 430 with 84000 miles. When I turn the key to start the engine I have to hold it for a few seconds, while there is no noise from the starter (initially I thought the battery is dead), and then it starts. When I bought it, a month ago, when I turned the key all the way it started, without the 2-3 seconds of delay. What seems to be the problem? Thanks.