An intake manifold runner control is an electronic system that gives data regarding linkage and plate position to the powertrain control module. The IMRC is housed inside an aluminium casting that stores a motorized actuator with air passages for each cylinder. The IMRC does not become active at engine speeds below 3,000 rotations per minute to allow its linkages to fully extend and air passages butterfly valves to close.
The IMRC is designed to allow the engine to operate under the best conditions in any speed level that the engine is generating. When the machine is using a small portion of its power, the intake manifold automatically becomes longer, which allows the engine to generate greater torque while staying smooth. When the engine revs up and needs more horsepower, the valve plates in the IMRC are open and shorten the intake manifold runners.
Some problems that can happen to the IMRC system include the clips that hold the linkage rods together breaking and engine deposits causing the valve plates to stick together over time. When the valve plates stick, the engine's power output can be compromised at higher speed requirements as well as causing strain to the system itself, leading to damage over time.