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The aneroid, thermostat and control valve each have a pin that extends into the housing and rests against the rocker. As altitude or temperature changes, the pins extend or retract, moving the rocker which in turn moves the correction lever.
The Governor Housing
It's What's on the inside that counts
While every part of Bosch fuel injection pumps is important, the interior is where the action happens. Despite a small footprint, dozens of moving parts all must function cohesively to get the exact fuel mixture injected when your engine needs it. If one component isn't working or was incorrectly adjusted, countless issues and symptoms will arise and prevent your classic car from functioning properly, if it runs at all. Mechanical Fuel Injection (MFI) is a complicated thing, but we're here to give you a jump-start on understanding the body and inner-workings of the Bosch fuel injection pump.
The featured illustration displays the linkage (green) between the rocker (red) and correction lever (orange), along with their relationship to the aneroid (light blue) and control valve (dark blue).
The photographs below show the location of each part in relation to running temperature with -20°C on the left followed by 20°C, 40°C, and warm-running. In the final image on the right, while running at warm temperatures, you can see the correction lever is almost parallel to the bottom of the housing opening, the correction lever pin is centered on the guide roller, and the spring to the left is fully compressed meaning no air is being allowed through the control valve.
INSIDE THE GOVERNOR At TEMPERATURE INTERVALS
The Control Valve
Getting your engine the air and fuel it needs.
The control valve sits atop the governor and connects to the thermostat, which, depending on the temperature, controls the amount of air and fuel that reach the engine, an essential part of Mechanical Fuel Injection (MFI). A pin, seen in teal on the illustration, reaches into the governor housing and, as temperature rises, extends from the control valve, compressing a spring and adjusting the rocker and the correction lever to the desired positions. In the fully extended, warm-running position, the pin compresses the spring completely, closing the valve and preventing air and fuel from entering from the injection pump.
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