Alexander, trust me the MB OM352 does not have any throttle butterfly nor EGR technology. The air goes through a cyclone and then a filter straight into the tappet cover (
top black stopper behing MB sign in this photo). It has an internal intake manifold. If you look at
this photo of it, you will notice a pivot plate left of the red oil level dipstick, connected to a spring and a shaft going into the picture to the left of the engine (rear side). This shaft is connected on the left side of the engine by solid linkages to the floor throttle pedal and by cable to the hand throttle lever. Following the linkage from the plate to the right, it passes behind the oil filter and connects on the rear of the injector pump (Unit bolted to side of engine in photo). Behind the injector pump is also the set screw for the idle speed. The right side of the pump, were the 6 injector lines exit contain the 6 variable stroke pistons that meters the fuel. The left part of the pump (with the vertical split) is the stroke drive unit into which the throttle linkage go. As you press the throttle it translate the movement into a larger stroke for the fuel pistons. On the left bottom (out of view) is a little cap which can be removed. Inside is a screw which you can adjust to increase the fuel quantity by adjusting the slope of the "delivery map" mechanically. This is the way this engine is tuned to various power outputs for different uses. On my Unimog I can still go higher in power output, but does not have a EGT gauge, which is essential to prevent melt down on long full power usage.
BTW, one of the classical, read old, reasons for diesel being lighter on fuel in town driving was that because they have no throttle butterfly there was no pumping loss like on a part throttle gas engine.
