Check that the potentiometer operating lever moves freely: it must turn 90°. Check not «sat down» whether a return spring.
Connect tester (in ohmmeter mode) to conclusions «A» And «E» potentiometer and measure the total resistance, which should be in the range of 1.3-2.5 kOhm.
If the total resistance is not within the specified limits, replace the 1st chamber throttle potentiometer.
Vehicles from model year 1986
The total resistance of the potentiometer is tested on the vehicle. It should be in the range of 1.4-2.6 to Ohm.