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Old 03-31-2009, 10:29 AM
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syljua syljua is offline
C140 CL500
 
Join Date: Jan 2005
Location: Norway
Posts: 132
Quote:
Originally Posted by Ivanerrol View Post
That vacuum line coming from the fuel regulator is not a vacuum line per se. That line goes to the hose that extends from the valve cover gasket to the air cleaner.
The purpose of that tube is to overflow fuel to the air intake in case the regulator diaphragm goes faulty. (Fire preventative.)
The line is there to regulate the fuel pressure in the rail
so that the pressure is at a constant level above pressure in the intake
(so that a set opening time of the injector will give the same
amount of fuel regardless of intake pressure). If the diaphragm goes
south, yes the fuel will be drawn to the intake, but thats secondary.

I made a video on checking the FPR last summer;
http://www.pvv.org/~syljua/merc/FuelPressureME.mov

This is for a M119, and I see now, that maybe the M103 FPR functions
differently?

br,
syljua
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1998 CL500 W140
1984 230E W123
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