I have a 1995 S600 coupe. After it has sat for about an hour, I have to hold the accelerator down in order to get it to start. If I do not hold the accelerator the engine will spin and hit but will not start. It will even kill the battery in this manner. Even if I hold the accelerator, it still spins for a while before it starts. I have replaced the fuel regulator, plugs, distributor caps and rotor buttons. Sometime after it starts I smell a strong smell of fuel. Does anyone have any idea what my problem may be?