190E won't idle
 

I hope some out there can help me.
I have a 1989 190E 2.6
This car was bought new...it has been well maintained.
The problem started after the car set for about a year. It ran ok, but would stall once in a while.
A mercedes mechanic suggested that the fuel distrbutor should be rebuilt...I sent it out and had it done.
When I replaced it the car ran good for about a 1000 miles. Then the stalling started again. I sent the fuel dist back to person that rebuilt it...He ran several tests and said it checked out ok. Since then I have replaced both fuel pumps, the fuel filter, the fuel pressure regulator, and even the fuel pump relay. Also replaced the 4 prong temp sensor, spark plugs and wires, cap and rotor.
The car will start but won't idle below 1000 rpms. I do notice that it seems to flood....I pulled the air box and there is fuel in the intake. If I lean the mixture screw the car won;t run at all. I have even tried a complete different fuel dist and air box....same problem. I don't know what else to check....The parts are way to expensive to just replace one at a time. CAN ANYONE HELP?? Thanks!!