Hi all!

I have a question about my 1985 500 SEC. On the front of the motor, just to the left of the idle control valve, is a unit, i dont know what it is, maybe a fuel accumulator, or regulator, it has fuel lines going to it, it also has a little vacuum line coming from the top, but the vacuum line is missing. I do not see any loose vacuum lines, and when i attach a vacuum line to it, the idle noticably changes, so it must be important! Sorry for my lack of knowledge, but i am new to mercedes motors. If anyone can tell me what this unit is, and also where the vacuum line for this unit is suppose to come from, i would really appreciate it! Any help i can get would be great!

Thanks again!