SYSTEM DESCRIPTION Fuel Pump Fuel Tank Fuel Pulsation Damper ISC Valve Pressure Regulator Cold Start Injector Air Flow Meter Air Temp. Sensor Start Injector Time Switch Throttle Position Sensor Oxygen Sensor Knock Sensor Water Temp. Sensor Distributor ECU Ignition Switch Speed Sensor Battery Terminal VF VSV for EGR Air Conditioner Ignition Coil w/Igniter Check Engine Warning Light Check Connector Neutral Start Switch (For A/T) The EFI used on Toyotas has three basic systems. FUEL SYSTEM An electric fuel pump supplies sufficient fuel, under a constant pressure, to the EFI injectors. These injectors inject a metered quantity of fuel into the intake manifold in accordance with signals from the ECU. Each injector injects, at the same time, one half of the fuel required for ideal combustion with each engine revolution. AIR INDUCTION SYSTEM The air induction system provides sufficient air for engine operation. ELECTRONIC CONTROL SYSTEM The 5M-GE engine is equipped with a Toyota Computer Control System (TCCS) which centrally controls the EFI, ESA, EGR, Diagnosis systems, etc. by means of Electronic Control Unit (ECU — formerly EFI computer) employing a microcomputer.