Ford Mustang/Capri 1979-1988 Repair Guide

Air Vane Meter Assembly


See Figure 1

The air vane meter assembly, found on the 4-140 turbo engine, is located between the air cleaner and the throttle body and is mounted on a bracket near the left or right hand corner of the engine compartment. The air vane meter contains two sensors which furnish input to the Electronic Control Assembly: a vane airflow sensor and a vane air temperature sensor. The air vane meter measures the mass of air flow to the engine. Air flow through the body moves a vane mounted on a pivot pin. This vane is connected to a variable resistor (potentiometer) which, in turn, is connected to a 5-volt reference voltage. The output of this potentiometer varies depending on the volume of air flowing through the sensor. The temperature sensor in the air vane meter measures the incoming air temperature. These two inputs, air volume and temperature, are used by the Electronic Control Assembly to compute the mass air flow. This valve is then used to compute the fuel flow necessary for the optimum air/fuel ratio which is fed to the injectors.

Click image to see an enlarged view

Fig. Fig. 1: Air vane meter assembly


  1. Loosen the hose clamp which secures engine air cleaner outlet hose to the vane meter assembly.
  3. Remove air intake and outlet tube from the air cleaner.
  5. Disengage four spring clamps and remove air cleaner front cover and air cleaner filter panel.
  7. Remove the two screw and washer assemblies which secure the air meter to its bracket. Remove the air vane meter assembly.
  9. Installation is the reverse of removal.