SFI SYSTEM


  1. CONSTRUCTION


    1. The intake air control valve is installed in the intake air surge tank assembly. It opens and closes to provide 2 effective intake manifold lengths.

    2. The ACIS actuator activates the intake air control valve based on signals from the ECM.

      B0023FQC01
      *1 Intake Air Control Valve *2 ACIS Actuator

  2. OPERATION


    1. While the engine is running at low or medium speed under high load, the ECM causes the ACIS actuator to close the intake air control valve. As a result, the effective length of the intake manifold is lengthened and the intake efficiency, in the medium speed range, is improved due to the dynamic effect (inertia) of the intake air, thereby increasing power output.

      Figure 1. When the intake air control valve closes

      B00234CE09

    2. Under any condition except when the engine is running at low or medium speed under high load, the ECM causes the ACIS actuator to open the intake air control valve. When the intake air control valve is open, the effective length of the intake air surge tank assembly is shortened and peak intake efficiency is shifted to the low-to-high engine speed range, thus providing greater output at low-to-high engine speeds.

      Figure 2. When the intake air control valve opens

      B0023M3E10