Mixture Ratio Feedback System: Operation: Notes

When engine coolant is below predetermined temperature of coolant switch, mixture ratio valve leans out air/fuel mixture. When engine coolant is above predetermined temperature of coolant switch and vehicle speed is above predetermined speed of speed switch, mixture ratio valve is activated and leans out air/fuel mixture.

Fig 1: Datsun 210 Mixture Ratio System

Courtesy of NISSAN NORTH AMERICA, INC.

System is used on California models only. 

When engine coolant is above the predetermined temperature of the coolant switch and vehicle speed is below the predetermined speed of the speed switch, mixture ratio valve is deactivated and air/fuel mixture is richened.

Fig 2: Datsun 310 Mixture Ratio System

Courtesy of NISSAN NORTH AMERICA, INC.

System is used on California models only.