Hello and welcome site, Im a brandnew member...I have a 1995 SL500. If I drive the car every day. It drives like a brand new car,,, If I let it sit a cpl weeks, The car has troubling starting , no Power, coughs, then after about 10 mins it runs perfect. I thoght it was a dirty fuel filter , I changed the filters and pumps, Its still doing it. Theres no check engine light . By the time i drove it to diagnostic it was running fine , so nothing showed up.... Any gueses ?