Partial Load Channel Heating Test (VW Transporter T3)

The carburetor has a heating element for heating the partial load channel. The heating element prevents the carburetor from icing. A defective heating element leads to transient disturbances during the cold season when warming up the engine; the engine suddenly stalls before it's warmed up.

Note: The test is performed on a cold engine (ambient temperature).

Turn on the ignition.



Disconnect connector "1" from the idle air control valve.

Disconnect the connector from heating element "2".

Connect the test lamp to connectors "1" and "3".

The control lamp should light up, otherwise replace the heating element.