I own a 1995 S600 coupe. After it sits for about 3 or 4 hours, it is extremely hard to start. The engine spins and spins and sometimes runs down the battery. After it starts there is a very pronounced smell of fuel. Does anyone have any idea what could be causing this? The car has 87,000 miles on it. Does this model have a reputation for leaky fuel injectors?

Have the fuel system pressure checked. There are several possibilities to look at.
*cold start valve(s)
*back flow valve at fuel pump
*leaky injectors
*fuel distributor
This is also the sequence I would look into the subject.
Good luck