Deceleration control system (Mazda Capella GC)

Contents: General description ⇓ Component check ⇓ Replacement of parts ⇓

General description

1. The throttle control system gradually closes the throttle so that excessive unburned fuel is not released into the exhaust, resulting in increased emissions.

2. The parts of this system are the flame arrester valve and (on models with manual transmission) a shock absorber on the carburetor that controls the throttle.

3. A sign of damage in the shock absorber is the immediate closing of the throttle when decelerating. A faulty valve may cause backfire and operate with the ignition off.

Component check

Flame arrester valve

4. Start the engine and place your hand under this valve.

5. Increase the engine speed to approximately 3000 rpm and then suddenly release the throttle. If the air coming from the valve is cut off, then it is working correctly.

6. Let the engine idle. Disconnect the air hose from the valve and close the open end of the hose. If the idle speed is significantly different from the speed before the hose was disconnected, the valve will leak and should be replaced.

Checking the flame arrester valve

Shock absorber

7. Quickly pull the throttle lever away from the shock absorber and check that the shock absorber rod moves freely. Release the throttle, lift it up and make sure it slowly returns to its original position after contacting the shock absorber rod.

8. To adjust the shock absorber, start the engine and connect the tachometer while idling at normal temperature. Slowly increase engine speed and check that the shock absorber rod separates from the control arm at approximately 2200 rpm. Loosen the lock nut and rotate the shock absorber to adjust it.

9. If the adjustment does not bring the shock absorber as given in the Specification, replace it with a new one.