The exhaust emission control device used on 1968-69 type 1 and 2 vehicles is the throttle valve regulator. This device holds the throttle open slightly on deceleration to prevent an excessively rich mixture.
The throttle regulator unit is of a one piece design, and mounted on the carburetor.
- The engine must be at operating temperature with the automatic choke fully open.
- Start the engine. Turn the regulator adjusting screw clockwise until the control rod just starts to move the throttle valve lever. The stop collar on the control rod will be against the regulator body. Engine speed should be 1,700-1,800 rpm.
- If the speed is too high, shorten the control rod.
- After adjustment, tighten the locknuts on the control rod.
- Turn the regulator adjusting screw counterclockwise until an idle speed of 850 rpm is obtained.
- Increase engine speed to 3,000 rpm, then release the throttle valve lever. The engine should take 3-4 seconds to return to idle.
Incorrect throttle regulator adjustment may cause erratic idle, excessively high idle speed, and backfiring on deceleration.