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Main Relay (Computer/Fuel System): Description and Operation

Circuit Description
The Multiport Fuel Injection (MFI) control system is an electronic fuel metering system with fuel injectors near inlet port of each cylinder The amount of fuel injection is determined by ECM according to engine speed and intake air-flow quantity measured. The emission control system includes oxygen sensor and catalystic converters. The MFI's three major functions are air-fuel mixture, idle speed and ignition timing control.