Vacuum line to fuel regulator
 

Hello all,

Does anyone know where the vacuum line connecting to the fuel regulator connects to in the engine bay? I changed the fuel filter/regulator of my 99 E55. However, I don't think the vacuum line is pulling any vacuum to the regulator. I don't know where the other end connected to.

Thanks,

Vincent

Hello, I finally found the answer. The vacuum line is connected to the return hose of the fuel tank. The design is different from most cars where the line is connected to the vacuum source in the intake manifold. I also discovered my fuel cap might be leaking, even though there is no check engine light. Not sure it is leaking when pressurized or under vacuum, but it created lots of fuel related problems.

was wondering the same recently, apparently this hose wont affect much if its disconnected even? im still not 100% sure about it