626 L4-2000 1998cc (1983)
Barometric Pressure Switch: Testing and Inspection
Fig. 34 Vacuum Switch
OPERATION
1.
While driving the vehicle at high altitudes, there is a tendency to accelerate more to make up for a lack of power.
2.
When the vacuum of the intake manifold nears the atmospheric pressure (less than 60 mm Hg), the vacuum switch, Fig. 34, will turn off and signal
to the control unit.
3.
The control unit will then send a signal to the A/F solenoid of the carburetor to supply more fuel.
Fig. 35 Inspection Of Vacuum Switch W/Voltmeter
TESTING ON THE VEHICLE
1.
Run engine at idle.
2.
Connect a voltmeter to the vacuum switch connector G terminal as in Fig. 35.
Voltage reading should be below 1.5V.
3.
Disconnect the vacuum sensing tube from the switch, and then plug the tube.
Voltage reading should be approximately 12V.
