Hatchback 4WD F4-1781cc 1.8L (1983)
Thermostatic Air Cleaner: Testing and Inspection
Visually inspect the system checking for any vacuum hoses that are damaged or improperly attached. Check for binding or damage to the air door
in the air cleaner housing. Apply vacuum to the air door controller and check to see that the door moves and the controller holds vacuum. If
system passes all visual checks proceed as follows:
a. When underhood temperatures are below 112 deg. F. the air door should be completely closed. Between 112 and 133 deg. F the door will be
partially open. From 133 deg. F. and higher the air door should be completely open. If any of these conditions are not met, check the vacuum
source to the air temperature sensor in the air cleaner assembly. If vacuum source is normal, replace the air temperature sensor.