'91 500SE W126 FPR vac connection

[Takernz_30]

hi guys!

My friend's '91 W126 500SE FPR vac has no connection. (maybe this is why the engine drank so much fuel than it should be). To where to connect the vacuum side of the FPR? Can I get the source vacuum from the door locks? (the gray plastic one in the 2nd photo).BTW, the plastic yellow vacuum line is from FPR.

photos:

[Necrosavant]

the fuel pressure regulator vac line is only a drip line if the regulator fails it goes into the little spot on the air cleaner breather hose

[Necrosavant]

i find it odd that the 91 has the green 2 sleve connector temp sensor for the cis where my 89 560 euro has the 3 pin black top

[Tomguy]

I'll move this from Vintage to general Tech Help for a better viewing audience Sorry I don't know your answer!

[duxthe1]

Necro has it right, not a vacuum connection, just a failsafe in case of diaphram rupture.

[Takernz_30]

Originally Posted by duxthe1

Necro has it right, not a vacuum connection, just a failsafe in case of diaphram rupture.

Ok, then, what controls the fuel pressure? as you see the photo, the reddish color surrounding the FD is the fuel but the FD is fine though, still puzzled by high fuel consumption, I suspect OVP, maybe busted? or fuel pump relay?

[Takernz_30]

Originally Posted by Tomguy

I'll move this from Vintage to general Tech Help for a better viewing audience Sorry I don't know your answer!

I'm sorry Tom, I thought this is general tech. wrong room

[duxthe1]

The regulator controls the fuel pressure and doesn't use a manifold vacuum reference to do so. Remember this is CIS not EFI. The regulator sets system pressure but the ECU is in charge of control pressure.