Fuel reservoir at front of fuel distributor
 

On my 2.3 I have been trying to track down a vacuum leak which is affecting performance. Previously posted as "Loping engine".
Upon testing the vacuum line that goes from the "fuel reservoir" to the air cleaner housing. The line does not hold a vacuum and I am not sure from the MB manuals that it is supposed to. When I pull on the rubber hose that comes out of the diaphragm end of the reservoir it will hold a vacuum. What does this vacuum line do and is this normal.
TIA
John O

????? Curious ??????
 

Can you be a little more desrcptive about which piece you need. I am not sure if you are refering to the return fuel pressure regulator or what?

It is the fuel pressure regulator that I was referring to.
John

The line that appears to be a vacuum line to the pressure reg valve, is not a vacuum line. it is a vent line. As the diaphram moves back and forth in the reg the area behind it must vent. To keep from pulling dirt and/or moisture the line is run to the area of the air filter.