1999 Pontiac Grand Am Extreemly Rich Starts

We very good gas mileage, 25 city 32 highway. It also is very responsive for a 4-cyl, just a touch of the accelerator and your off to the races. The Rich Start problem has been getting slightly worse each year for the past 5 years. When the engine is cold it will start by itself but you can smell rich exhaust if the windows are down. When Hot after being off for 10 minutes it will not start unless you slowly press down on the accelerator while cranking. Hot or Cold the idle immediately comes down to normal in 5 or less seconds. Recently the problem has been getting worse and now just as it starts there is a large cloud of blue smoke at the exhaust. Oil level does not show any usage yet.