WORKSHOP MANUAL - lombardini service

Settings
9
E.G.R. calibration
Mount a T-branch on vacuum valve - E.G.R. valve connection pipe
1, and connect it to a vacuum pressure gauge with 1 bar bottom
scale so as to be able to read the degree of vacuum within the pipe.
Note: It is also possible to use a mercury column, 1 metre long,
since the maximum suction pressure exerted by the vacuum
pump is 720 mmHg.
Adjust the position of the accelerator lever via the regulator block, so
that the internal adjusting nut 2, is about 5 mm from the end of the
thread.
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Accelerate the engine up to 3.600 rpm (with valve closed: this
means that the value showed on the vacuum pressure gauge or on
the mercury column should be 0.
In case it is different from zero, adjust the regulator block nuts to
move it, in relation to the rod 3, in the direction that goes from the
flywheel to the timing.
With the brake at a braking curve N=constant, “load” the engine
slowing it down to 2.800 rpm.
Acting on the accelerator look for the E.G.R. valve closing point
(pressure of the vacuum pressure gauge or mercury gauge equal to
zero).
Note: Pay attention to determine the precise closing point: by
slightly accelerating the engine the vacuum value in the
E.G.R. operation pipe should immediately increase.
Measure the engine consumption in order to calculate the mm3/
stroke value.
If the calculated value is less than 18.8 mm 3 /stroke, adjust the
adjusting nut making it closer to the end of the rod 3 to “increase the
calibration”.
When the required value of 18.8 mm 3 /stroke has been reached (and
a power of around 7 KW) tighten the adjusting nuts.
FOCS Workshop Manual_cod. 1.5302.858_1° ed_ rev. 00
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