Deceleration Fuel Cut System: Operation

The slow speed circuit in carburetor operates except during prolonged periods of deceleration at high engine speeds. Under these conditions, the computer turns off the fuel cut solenoid valve and the mixture is leaned out. This prevents overheating and afterburning in the catalytic converter.

The Tercel system is operated only by a vacuum switch. There is no speed sensor or computer, and the VCV in the vacuum line is used only for hose connection, not for vacuum control.