SFI SYSTEM


  1. FUNCTION


    1. The Dual VVT-i system is designed to control the intake and exhaust camshafts within a range of 40° and 45° respectively (of crankshaft angle) to provide valve timing that is optimally suited to engine operating conditions. This improves torque in all speed ranges as well as increasing fuel economy and reducing exhaust emissions.

      A00XRILC01
      *1 Camshaft Timing Oil Control Valve Assembly (Intake) *2 Camshaft Timing Oil Control Valve Assembly (Exhaust)
      *3 Crank Position Sensor *4 E. F. I. Engine Coolant Temperature Sensor
      *5 Throttle Position Sensor *6 Intake Mass Air Flow Meter Sub-assembly
      *7 ECM *8 Cam Position Sensor (No. 1 Crank Position Sensor) (Exhaust)
      *9 Cam Position Sensor (No. 1 Crank Position Sensor) (Intake) - -

    2. The Dual VVT-i system delivers excellent benefits during the vehicle operation states shown in the table below.

      A00XRQ9E01
      Operation State Objective Effect
      During Idle Eliminating overlap to reduce blow back to the intake side.

      • Stabilized idle speed

      • Better fuel economy
      Upon Starting and Stopping the Engine Eliminating overlap to minimize blow back to the intake side. Improved startability
      At Light Load Eliminating overlap to reduce blow back to the intake side. Ensured engine stability
      At Medium Load Increasing overlap to increase internal EGR to reduce pumping losses.

      • Better fuel economy

      • Improved emission control
      In Low to Medium Speed Range with Heavy Load Advancing the intake valve close timing for volumetric efficiency improvement. Improved torque in low to medium speed range
      In High Speed Range with Heavy Load Retarding the intake valve close timing for volumetric efficiency improvement. Improved output
      At Low Temperatures Eliminating overlap to reduce blow back to the intake side during fast idle.

      • Stabilized idle speed

      • Better fuel economy